<PAGE>
 
                    U.S. SECURITIES AND EXCHANGE COMMISSION
                            Washington, D.C. 20549


                                   FORM 10-Q

(Mark One)
[X]    QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15 (d) OF THE SECURITIES
EXCHANGE ACT OF 1934
For the quarterly period ended December 31, 1998

[_] TRANSITION REPORT PURSUANT TO SECTION 13 OR 15 (d) OF THE SECURITIES
EXCHANGE ACT OF 1934
For the transition period from _______________to________________

                        Commission file number: 1-9083
                                        
                             POLYPHASE CORPORATION
            (Exact name of registrant as specified in its charter)

                 NEVADA                                         23-2708876
     (State or other jurisdiction of                        (I.R.S. Employer
      incorporation or organization)                        Identification No.)

                            4800 BROADWAY, SUITe A
                             ADDISON, TEXAS 75001
                   (Address of principal executive offices)

                                (972) 386-0101
             (Registrants's telephone number, including area code)


Indicate by check mark whether the registrant (1) has filed all reports required
to be filed by Section 13 or 15 (d) of the Exchange Act during the past 12
months ( or for such shorter period the registrant was required to file such
reports), and (2) has been subject to such filing requirements for the past 90
days.
Yes    X        No _______
    --------                  

Indicate the number of shares outstanding of each of the issuer's classes of
common stock, as of the latest practicable date.

Common Stock, $.01 par value                               16,657,321
                                                 -------------------------------
                                                 Outstanding at February 5, 1999
<PAGE>
 
                             POLYPHASE CORPORATION
                                   FORM 10-Q
                        QUARTER ENDED DECEMBER 31, 1998

--------------------------------------------------------------------------------


                               TABLE OF CONTENTS
                               -----------------

<TABLE> 
<CAPTION> 
PART I. FINANCIAL INFORMATION                          Page No.
-----------------------------                          --------
<S>                                                    <C> 
Item 1. Financial Statements
 
Consolidated Condensed Balance Sheets as of
   December 31, 1998 and September 30, 1998                2 
                                                           
Consolidated Condensed Statements of                       
  Operations for the Three Months Ended                    
  December 31, 1998 and 1997                               4
                                                           
Consolidated Condensed Statements of                       
  Cash Flows for the Three Months Ended                    
  December 31, 1998 and 1997                               6
                                                           
Notes to Consolidated Condensed Financial Statements       8
 
Item 2. Management's Discussion and Analysis of
 Financial Condition and Results of Operations            11

Item 3. Quantitative and Qualitative Disclosures
   about Market Risk                                      13

PART II - OTHER INFORMATION
---------------------------

Item 1. Legal Proceedings                                 14
                                                           
Item 6. Exhibits and Reports on Form 8-K                  14
                                                           
Signature Page                                            15
</TABLE>

                                      -1-
<PAGE>
 
                    POLYPHASE CORPORATION AND SUBSIDIARIES
                     CONSOLIDATED CONDENSED BALANCE SHEETS

                                    Assets

<TABLE> 
<CAPTION> 
                                                 (Unaudited)
                                                 December 31,      September 30,
                                                 -----------       ------------ 
                                                     1998              1998
                                                 -----------       ------------ 
<S>                                              <C>               <C>  
Current assets:                                 
 Cash                                            $   850,205        $  423,957
 Receivables, net of allowance for doubtful                      
  accounts of $526,635 and $562,800                              
    Trade accounts                                13,125,310        13,839,250
    Current portion of sales contracts             3,653,222         3,879,420
    Notes receivable                               1,839,846         1,813,232
 Inventories                                      36,671,181        34,568,628
 Prepaid expenses and other                          784,055           527,999
                                                 -----------       ----------- 
    Total current assets                          56,923,819        55,052,486
                                                 -----------       -----------
                                                                 
Property and equipment:                                          
 Land                                                432,000           432,000
 Buildings and improvements                        4,450,753         4,054,854
 Machinery, equipment and other                    9,582,330         9,490,827
                                                 -----------       ----------- 
                                                  14,465,083        13,977,681
 Accumulated depreciation                          7,910,855         7,526,281
                                                 -----------       ----------- 
                                                   6,554,228         6,451,400
                                                 -----------       -----------
Other assets:                                                    
 Noncurrent receivables                                          
   Sales contracts                                 1,283,565         1,363,039
   Related parties                                   830,983           670,655
 Excess of cost over fair value of net assets                          
  of businesses acquired, net of accumulated                         
  amortization of $3,387,066 and $3,183,743       13,211,673        13,414,996
 Other intangible assets                           2,185,519         2,494,754
 Restricted cash                                     644,171           672,898
 Other                                             1,413,551         1,425,147
                                                 -----------       -----------
                                                  19,569,462        20,041,489
                                                 -----------       -----------  

                                                 $83,047,509       $81,545,375
                                                 ===========       ===========
</TABLE>


                  The accompanying notes are an integral part
                  of these consolidated financial statements.

                                      -2-
<PAGE>
 
                    POLYPHASE CORPORATION AND SUBSIDIARIES
               CONSOLIDATED CONDENSED BALANCE SHEETS (CONTINUED)


                      LIABILITIES AND STOCKHOLDERS' EQUITY

<TABLE>
<CAPTION>
                                                              (Unaudited)
                                                              December 31,   September 30,
                                                              -----------    ------------   
                                                                 1998            1998
                                                              -----------    ------------   
<S>                                                           <C>            <C> 
Current liabilities:                                 
 Notes payable                                                $ 14,139,109    $ 14,409,681
 Note payable and accrued interest to related party             16,722,729      16,307,405
 Accounts payable                                                7,740,095       6,085,703
 Accrued expenses and other                                      3,743,904       3,514,685
 Current maturities of long-term debt                            4,283,333       3,533,333
                                                              ------------    ------------ 
    Total current liabilities                                   46,629,170      43,850,807
                                                     
Long term debt, less current maturities                         28,256,370      29,220,972
Reserve for credit guarantees                                      644,171         672,898
                                                              ------------    ------------ 
    Total liabilities                                           75,529,711      73,744,677
                                                              ------------    ------------ 
                                                     
Warrants to purchase common stock                    
 in subsidiary                                                   1,200,000       1,200,000
                                                     
Stockholders' equity:                                
 Preferred stock, $.01 par value, authorized         
    50,000,000 shares, issued and outstanding        
    99,034 and 115,000 shares, respectively                            990           1,150
 Common stock, $.01 par value, authorized            
   100,000,000 shares, issued and outstanding        
   16,002,321 and 15,080,050 shares, respectively                  160,023         150,800
 Paid-in capital                                                28,705,331      28,623,811
 Accumulated deficit                                           (21,573,227)    (21,199,744)
 Notes receivable                                                 (975,319)       (975,319)
                                                              ------------    ------------ 
   Total stockholders' equity                                    6,317,798       6,600,698
                                                              ------------    ------------ 

                                                              $ 83,047,509    $ 81,545,375  
                                                              ============    ============
</TABLE>                                             

                  The accompanying notes are an integral part
                  of these consolidated financial statements.

                                      -3-
<PAGE>
 
                    POLYPHASE CORPORATION AND SUBSIDIARIES
                CONSOLIDATED CONDENSED STATEMENTS OF OPERATIONS
                                  (Unaudited)

<TABLE> 
<CAPTION> 
                                                               For the Three Months Ended
                                                                     December 31,
                                                             ------------------------------                           
                                                                   1998            1997
                                                                -----------   ----------- 
<S>                                                             <C>           <C>
Net revenues                                                    $36,055,968   $37,392,317
                                                        
Cost of sales                                                    29,900,516    30,425,160
                                                                -----------   ----------- 
Gross profit                                                      6,155,452     6,967,157
                                                        
Selling, general and administrative expenses                      4,512,351     4,596,486
                                                                -----------   -----------
Operating income                                                  1,643,101     2,370,671
                                                                -----------   ----------- 
                                                        
Other income (expenses):                                
 Interest expense                                                (2,166,149)   (1,849,768)
 Interest income and other                                          182,663       (10,950)
 Gain on sale of assets                                                   -       987,857
                                                                -----------   -----------
       Total other income (expenses)                             (1,983,486)     (872,861)
                                                                -----------   ----------- 
Income (loss) before income taxes and extraordinary item           (340,385)    1,497,810
Income taxes                                                              -             -
                                                                -----------   ----------- 
Net income (loss) before extraordinary item                        (340,385)    1,497,810
                                                        
Extraordinary item:                                     
 Early extinguishment of debt                                             -      (616,239)
                                                                -----------   ----------- 
Net income (loss)                                                  (340,385)      881,571
                                                        
Dividends on preferred stock                                        (33,098)      (40,875)
                                                                -----------   ----------- 
Net income (loss) attributable to common stockholders           $  (373,483)  $   840,696
                                                                ===========   ===========
</TABLE>

                   The accompanying notes are an integral part
                  of these consolidated financial statements.

                                      -4-
<PAGE>
 
                     POLYPHASE CORPORATION AND SUBSIDIARIES
          CONSOLIDATED CONDENSED STATEMENTS OF OPERATIONS (continued)
                                  (Unaudited)

<TABLE> 
<CAPTION> 
                                                   For the Three Months Ended
                                                            December 31,
                                                   ---------------------------
                                                        1998          1997
                                                   ------------    -----------
<S>                                                     <C>            <C> 
Basic income (loss) per common share:

 Income (loss) before
  extraordinary item                                    $(.02)         $ .10
                                                                                
 Extraordinary item                                         -           (.04)
                                                        -----          ----- 
                                                              
 Net income (loss) per common share-basic               $(.02)         $ .06
                                                        =====          ===== 
                                                              
Diluted income (loss) per common share:                       
                                                              
 Income (loss) before                                         
  extraordinary item                                    $(.02)         $ .09
                                                                           
 Extraordinary item                                         -           (.04)
                                                        -----          ----- 
                                                                       
 Net income (loss) per common share-diluted             $(.02)         $ .05
                                                        =====          ===== 
</TABLE> 

                  The accompanying notes are an integral part
                  of these consolidated financial statements.

                                      -5-
<PAGE>
 
                    POLYPHASE CORPORATION AND SUBSIDIARIES
                CONSOLIDATED CONDENSED STATEMENTS OF CASH FLOWS
                                  (UNAUDITED)


<TABLE> 
<CAPTION> 
                                                                 For the Three Months Ended
                                                                        December 31,       
                                                                 --------------------------
                                                                     1998           1997    
                                                                 -----------    ----------- 
<S>                                                              <C>            <C>          
Cash flow provided by (used in) operating activities:
 Net income (loss)                                                $  (340,385)  $   881,571 
Adjustments to reconcile net income (loss)                                                  
 to net cash provided by (used in ) operating                                               
 activities:                                                                                
  Depreciation and amortization                                     1,004,932     1,203,606 
  Provision for doubtful accounts                                           -        50,000 
  Gain on sale of assets                                                    -      (987,857)
Extraordinary item-early extinguishment of debt                             -       616,239 
Changes in:                                                                                 
  Accounts and sales contracts receivable                           1,019,612    (2,524,535)
  Inventories                                                      (2,102,553)   (1,766,038)
  Prepaid expenses and other                                         (244,460)      (53,919)
  Accounts payable                                                  1,654,392       887,332 
  Accrued expenses and other                                          312,002       393,668  
                                                                  -----------   -----------  
     Net cash provided by (used in )
      operating activities                                          1,303,540    (1,299,933)
                                                                  -----------   -----------  

Cash flows provided by (used in) investing activities:
  Notes and other receivables                                         (26,614)     (914,308)
  Receivables from related parties                                   (160,328)        8,963 
  Capital expenditures, net                                          (487,402)     (252,289) 
                                                                  -----------   -----------  
     Net cash used in
      investing activities                                           (674,344)   (1,157,634)
                                                                  -----------   -----------  
</TABLE> 

                  The accompanying notes are an integral part
                  of these consolidated financial statements.

                                      -6-
<PAGE>
 
                    POLYPHASE CORPORATION AND SUBSIDIARIES
          CONSOLIDATED CONDENSED STATEMENTS OF CASH FLOWS (continued)
                                  (Unaudited)

<TABLE>
<CAPTION>
                                                             For the Three Months Ended
                                                                     December 31,
                                                             --------------------------
                                                                 1998           1997
                                                             -----------   ------------ 
<S>                                                          <C>           <C> 
Cash flows provided by (used in) financing activities:
  Borrowings (principal payments) under line of
   credit arrangements, net                                   $  351,014   $  1,282,242
  Borrowings (principal payments) on other notes payable
   and long-term debt, net                                      (520,864)    24,773,669
  Principal payments on term notes                                     -     (1,982,280)
  Principal payments on convertible bonds                              -     (4,300,000)
  Principal payments on subordinated debentures                        -    (13,000,000)
  Redemption of Overhill warrants                                      -     (2,000,000)
  Deferred financing costs                                             -     (2,753,552)
  Dividends on preferred stock                                   (33,098)       (40,875)
  Stock issuance costs                                                 -        (17,500)
                                                             -----------   ------------ 
   Net cash provided by (used in)
     financing activities                                       (202,948)     1,961,704
                                                             -----------   ------------ 
Net increase (decrease) in cash                                  426,248       (495,863)
Cash - beginning of period                                       423,957      1,064,259
                                                             -----------   ------------  
Cash - end of period                                          $  850,205   $    568,396
                                                             ===========   ============

Supplemental schedule of cash flow information:
 Cash paid during the period for :
  Interest                                                    $1,957,148   $  1,815,288
  Income taxes                                                $        -   $          -
</TABLE>

  Supplemental schedule of noncash investing and financing activities:

  In December 1997, in connection with the Overhill Farms credit agreement,
  warrants were issued having an estimated fair market value of $1,200,000.

  In connection with the repayment of certain indebtedness to Merrill Lynch in
  December 1997, the Company issued warrants covering 210,000 shares exercisable
  at $.01 per share and 210,000 shares exercisable at $1.125 per share.  Such
  warrants were assigned a value of $175,000.

  In December 1998, the Company made a partial payment on a lawsuit obligation,
  together with certain associated expenses, by issuing 150,000 shares of common
  stock.


                  The accompanying notes are an integral part
                  of these consolidated financial statements.

                                      -7-
<PAGE>
 
                    POLYPHASE CORPORATION AND SUBSIDIARIES
             NOTES TO CONSOLIDATED CONDENSED FINANCIAL STATEMENTS
                               DECEMBER 31, 1998


1.   NATURE OF BUSINESS

     Polyphase Corporation (the "Company" or "Polyphase") is a diversified
     holding company that, through its subsidiaries, operates in three industry
     segments: the food segment, the forestry segment and the transformer
     segment. The food segment (the "Food Group"), which consists of the
     Company's wholly-owned subsidiary Overhill Farms, Inc. ("Overhill"),
     produces high quality entrees, plated meals, soups, sauces and poultry,
     meat and fish specialities. The forestry segment ("Forestry Group"), which
     consists of the Company's wholly-owned subsidiary Texas Timberjack, Inc.
     ("TTI") and TTI's majority-owned subsidiaries Southern Forest Products LLC
     ("SFP") and Wood Forest Products LLC ("WFP"), distributes, leases and
     provides financing for industrial and commercial timber equipment and is
     also engaged in certain related timber and sawmill operations. The
     transformer segment (the "Transformer Group"), which consists of the
     Company's wholly-owned subsidiary Polyphase Instrument Co. ("PIC"),
     manufactures and markets electric transformers, inductors and filters.
 
 
2.   BASIS OF PRESENTATION

     The consolidated financial statements include the accounts of the Company,
     its wholly-owned subsidiaries and its majority-owned subsidiaries. All
     material intercompany accounts and transactions are eliminated. Certain
     prior year amounts have been reclassified to conform to the 1998
     presentation.

     The financial statements included herein have been prepared by the Company,
     without an audit, pursuant to the rules and regulations of the Securities
     and Exchange Commission. Certain information and footnote disclosures
     normally included in financial statements prepared in accordance with
     generally accepted accounting principles have been condensed or omitted
     pursuant to such rules and regulations. The Company believes that the
     disclosures are adequate to make the information presented not misleading.
     The information presented reflects all adjustments (consisting solely of
     normal recurring adjustments) which are, in the opinion of management,
     necessary for a fair statement of results for the interim periods when read
     in conjunction with the financial statements and the notes thereto included
     in the Company's latest financial statements filed as part of Form 10-K for
     the year ended September 30, 1998.

3.   TAXES

     For the quarter ended December 31, 1998, the actual Federal income tax
     expense attributable to income from continuing operations differed from the
     net amounts recorded by the Company. The Company's subsidiaries recorded a
     provision for Federal income taxes of approximately $75,000 using the
     statutory tax rate of 34% and then applied a like amount of the existing
     valuation allowance, resulting in a net provision for the quarter of zero.
     As of December 31, 

                                      -8-
<PAGE>
 
     1998, the Company had a remaining valuation allowance of approximately $5.4
     million and net operating loss carryforwards of approximately $12.0
     million.


4.   EARNINGS PER SHARE


     The following table sets forth the computation of basic and diluted
     earnings per share:

<TABLE>
<CAPTION>
                                                                      December 31,        
                                                                  1998          1997      
                                                             -----------    -----------   
     <S>                                                     <C>            <C>           
     Numerator:                                                                         
        Net income (loss) before extraordinary item          $  (340,385)   $ 1,497,810   
        Extraordinary item                                             -       (616,239)  
                                                             -----------    -----------   
                                                                (340,385)       881,571   
        Preferred dividends                                      (33,098)       (40,875)  
                                                             -----------    -----------   
        Income (loss) attributable to common stockholders    $  (373,483)   $   840,696   
                                                             ===========    ===========   
                                                                                          
     Denominator:                                                                       
        Denominator for basic earnings per share-                                         
          weighted average shares                             15,396,070     13,987,226   
                                                                                          
     Effect of dilutive securities (a):                                                   
        Convertible preferred stock                                    -      1,071,185   
        Stock options                                                  -        317,008   
        Warrants                                                       -         62,129   
                                                             -----------    -----------   
        Dilutive potential common shares                               -      1,450,322   
                                                             -----------    -----------   
        Denominator for diluted earnings per share            15,396,070     15,437,548   
                                                             ===========    ===========    
</TABLE>

     (a)  Dilutive potential common shares were excluded from the computation in
          1998 since their effect would have been antidilutive.


5.   STOCKHOLDERS' EQUITY

     During the three months ended December 31, 1998, the holder of the
     Company's Series A-3 Preferred Stock converted a total of 15,966 shares of
     such stock, together with accrued dividends of $57,784, into a total of
     772,271 shares of common stock. Based upon the market price of the
     Company's common stock as of December 31, 1998, the holder would have been
     entitled to approximately 3.5 million common shares upon conversion of its
     remaining preferred stock and accrued dividends. Pursuant to a conversion
     of the Series A-3 Preferred Stock in January 1999, the holder was issued an
     additional 375,000 shares of common stock. The same holder has requested a
     further conversion of the Series A-3 Preferred Stock into 400,000 common
     shares.

                                      -9-
<PAGE>
 
     The Company, during the three months ended December 31, 1998, entered into
     an agreement, whereby the Company agreed to pay a $500,000 judgment
     relating to certain litigation in fiscal 1998, in monthly payments of
     $8,000 (including interest at 10% per annum) over an eighteen month period,
     with a balloon payment due at the end of that period. In connection
     therewith, the Company, during December 1998, issued 150,000 shares of its
     common stock as partial payment against the judgment, together with certain
     costs associated therewith. Also in connection with this agreement, an
     additional issuance of 150,000 shares was made in January 1999 in further
     payment of the obligation.
                                       -10-
<PAGE>
 
ITEM 2. MANAGEMENT'S DISCUSSION  AND ANALYSIS

RESULTS OF OPERATIONS

Certain statements contained in this Form 10-Q that are not historical facts,
including, but not limited to, any projections contained herein, are forward-
looking statements and involve a number of risks and uncertainties.  The actual
results of the future events described in such forward-looking statements in
this Form 10-Q could differ materially from those stated in such forward-looking
statements.  Among the factors that could cause actual results to differ
materially from the forward-looking statements are: adverse economic conditions,
industry competition and other competitive factors, government regulation and
possible future litigation.

Revenues for the three months ended December 31, 1998 decreased $1,336,000 (4%)
to $36,056,000 from $37,392,000 during the three months ended December 31, 1997.
Operating income decreased $728,000 (31%) to $1,643,000 from $2,371,000 during
the comparable period.  The decrease in sales during the first quarter was
primarily attributable to lower demand for heavy equipment at Texas Timberjack.

Net income before extraordinary item for the three months ended December 31,
1998 decreased $1,838,000 to a net loss of $340,000 from net income of
$1,498,000 during the three months ended December 31, 1997.  The decrease in net
income is attributable to lower revenues and  gross margins coupled with
increases in selling, general and administrative expenses at TTI.  Net income
for the period ended December 31, 1997, included a one time gain of $988,000
from the sale of the Company's corporate headquarters in December 1997.  The
Company realized a net loss for the three months ended December 31, 1997
of $373,000, as compared to net income of $841,000 in the comparable period of
fiscal 1998.

Revenues for the Food Group for the three months ended December 31, 1998
increased $835,000 (4%) to $24,059,000 from $23,223,000 for the three months
ended December 31, 1997.  Operating income for the three months ended December
31, 1997 increased $54,000 (4%)  to $1,402,000 from $1,348,000 for the three
months ended December 31, 1997.  Overhill's increased operating income was
primarily due to slight increases in gross margins and a reduction in general
and administrative expenses as management has reduced selling expenses related
to the retail business.

Revenues for the Forestry Group for the three months ended December 31, 1998
decreased $2,463,000 (19%) to $10,796,000 from $13,259,000 for the three months
ended December 31, 1997, while operating income for the for the three months
ended December 31, 1998 decreased $1,184,000 (86%) to $190,000 from $1,374,000
for the three months ended December 31, 1997.  The decrease in revenue and
operating income was primarily due to softness in the timber market during the
period resulting in fewer sales of equipment.  For the three months ended
December 31, 1998 the Texas Timberjack subsidiaries contributed revenues of
$1,539,000 and a net loss of  $83,000 to the consolidated amounts.

Revenues for the Transformer Group for the three months ended December 31, 1998
increased $291,000 (32%) to $1,201,000 from $910,000 for the three months ended
December 31, 1997, while operating income for the for the three months ended
December 31, 1998  increased $6,000 (100%).

                                      -11-
<PAGE>
 
LIQUIDITY AND CAPITAL RESOURCES

During the three months ended December 31, 1998, the Company's operating
activities provided cash of approximately $1,303,000 compared to a use of cash
of $1,264,000 during the comparable period in fiscal 1998. The increased cash
provided over the comparable period, resulted primarily from  increases in
accounts payable and decreases in receivables.

During the three months ended December 31, 1998, cash used in investing
activities was approximately $674,000 compared to a use of cash of $1,158,000
during the comparable period in fiscal 1998.  The Company's use of cash in the
current period consisted primarily of capital expenditures at Texas Timberjack
and its sawmill subsidiary.

During the three months ended December 31, 1998, cash used in financing
activities was approximately $203,000 as compared to cash provided of $1,962,000
in the comparable period in fiscal 1998.  The source of cash during the prior
period consisted primarily of net proceeds from the approximate $24.2 million
loan facility at Overhill Farms.

The Company plans to continue its program of expansion and diversification
through the acquisition of additional operating companies.  Funding for these
acquisitions is anticipated to come primarily from a combination of internally
generated funds and from additional borrowings.  The Company also has principal
payment obligations  to Merrill Lynch, Long Horizons and Mr. Harold Estes.  The
Company's management believes that cash generated from operations, together with
available lines of credit, possible refinancing and contemplated debt and/or
equity placements, will be sufficient to meet the Company's liquidity
requirements for the next twelve months.

YEAR 2000

The Company has initiated a Year 2000 program to identify and address issues
associated with the ability of its business systems and equipment to properly
recognize the Year 2000.  The purpose of this effort is to avoid interruption of
the operations of the Company as a result of the century change that will occur
on January 1, 2000.  The Company's program includes review of its software
systems, review of its operating systems, upgrade or retirement of non-compliant
hardware and contacting key suppliers to assess their Year 2000 readiness.

The Food Group is completing the installation of a new integrated accounting,
inventory, sales and purchasing system to replace the existing manual and
computer systems supporting operations.  The system software and hardware has
been certified by the vendor to be Year 2000 compliant and has been implemented
as a parallel system.  The Forestry Group has reviewed its existing software and
is the process of completing an upgrade modification.  The corporate office's
hardware and software systems are in the process of upgrading for obsolescence,
which complements the Year 2000 Project. Each group will retire or replace its
existing hardware as deemed necessary and should be completely tested and on
line by June 1999.

The Company began the second phase of its Year 2000 compliance project in late
January.  The Company's subsidiaries are contacting key vendors to assess their
Year 2000 readiness and evaluate 

                                      -12-
<PAGE>
 
the effect of non-compliance on the Company's future business.

Despite efforts to address the Year 2000 problem, there can be no guarantee that
critical suppliers or entities on which the Company relies will be converted on
a timely basis.  The Company believes, based upon preliminary findings, that
most vendors are performing internal Year 2000 projects similar to the Company's
and that non-compliant vendors will offer alternative measures for time
sensitive products.  Contingency plans for obtaining goods and services from
non-compliant vendors will be addressed on a case by case basis.

To date, the Company has had no material expenditures for direct Year 2000
compliance procedures. The Company believes that neither the cost of its planned
upgrade and modification program nor a failure to timely complete such program,
will have a material adverse effect on the Company's financial condition,
results of operations or cash flows.


ITEM 3. QUANTITATIVE AND QUALITATIVE DISCLOSURES ABOUT MARKET RISK

The Company does not own, nor does it have an interest in any market risk
sensitive investments.

                                      -13-
<PAGE>
 
                          PART II - OTHER INFORMATION


ITEM 1.  LEGAL PROCEEDINGS

The Company and its subsidiaries are involved in certain legal actions and
claims arising in the ordinary course of business.  Management believes (based
on advice of legal counsel) that such litigation and claims will be resolved
without material effect on the Company's financial position or results of
operations.


ITEM 6.  EXHIBITS AND REPORTS ON FORM 8-K.

         (a) Exhibits
 
         27  Financial Data Schedule

         (b) Reports on Form 8-K - The following reports were filed on Form 8-K
during the quarter ended December 31, 1998.

          NONE

                                      -14-
<PAGE>
 
                                  SIGNATURES


In accordance with the requirements of the Exchange Act, the registrant caused
this report to be signed on its behalf by the undersigned, thereunto duly
authorized.


                                                    POLYPHASE CORPORATION
                                                    (REGISTRANT)
                                                    
                                                    
Date: February 12, 1999                             
                                                    By: /s/ James Rudis
                                                        ------------------------
                                                        James Rudis
                                                        President
                                                    
                                                    
                                                    
Date: February 12, 1999                             
                                                    By: /s/ William E. Shatley
                                                        ------------------------
                                                        William E. Shatley
                                                        Chief Financial Officer

                                      -15-
<PAGE>
 
                               INDEX TO EXHIBITS


          Exhibit No.                                     Exhibit
         -------------                            -----------------------

            27                                    Financial Data Schedule