<PAGE>

                                                                   EXHIBIT 10.55


                        CONSENT AND FIRST AMENDMENT TO
                         SECURITIES PURCHASE AGREEMENT
                         -----------------------------

     THIS CONSENT AND FIRST AMENDMENT TO SECURITIES PURCHASE AGREEMENT is
entered into as of the 23rd day of August 2000 (this "Consent and Amendment"),
                                                      ----------- ---------
by and among OVERHILL FARMS, INC., a Nevada corporation (the "Company"), LEVINE
                                                              -------
LEICHTMAN CAPITAL PARTNERS II, L.P., a California limited partnership (the
"Purchaser"), POLYPHASE CORPORATION, a Nevada corporation ("Parent"), and
----------                                                  ------
OVERHILL L. C. VENTURES, INC., a California corporation ("Overhill Ventures").
                                                          -------- --------

                             R  E  C  I  T  A  L  S
                             -  -  -  -  -  -  -  -

     A.  The parties hereto entered into that certain Securities Purchase
Agreement dated as of November 24, 1999 (as amended, supplemented or otherwise
modified from time to time, the "Securities Purchase Agreement"), pursuant to
                                 -----------------------------
which, among other things, the Company issued and sold the Securities to the
Purchaser, all on the terms and subject to the conditions set forth in the
Securities Purchase Agreement and the other Investment Documents.  Unless
otherwise indicated, capitalized terms used herein shall have the meanings
assigned to such terms in the Securities Purchase Agreement.

     B.  The Company has advised the Purchaser that it wishes to purchase from
SSE Manufacturing, Inc., a California corporation (the "Seller"), on the terms
                                                        ------
and subject to the conditions set forth in an Asset Purchase Agreement dated as
of August 7, 2000 (the "SSE Asset Purchase Agreement"), between the Company and
                        ----------------------------
the Seller, the Assets (as such term is defined in the SSE Asset Purchase
Agreement).

     C.  The Company has further advised the Purchaser that it intends to borrow
the funds necessary to finance the cash portion of the Price (as such term is
defined in the SSE Asset Purchase Agreement) from Union Bank of California,
N.A., as "Bank" under the Senior Credit Agreement (the "Senior Lender"),
                                                        -------------
pursuant to a First Amendment to Loan and Security Agreement dated as of August
23, 2000 (the "Senior Lender First Amendment"), between the Company and the
               -----------------------------
Senior Lender, and to execute and deliver an unsecured promissory note in the
principal amount of $900,000 for the remaining balance of the Price.

     D.  The consummation of the purchase and sale of the Assets and the other
transactions contemplated by the SSE Asset Purchase Agreement (collectively, the
"Transactions") would, among other things, violate Sections 2.1A (Limitations on
 ------------
Indebtedness) and 2.3A (Limitations on Investments) of Annex A to the Securities
Purchase Agreement, as well as trigger an Event of Default under Section 10.1(b)
of the Securities Purchase Agreement.

     E.  The Company has requested that the Purchaser consent to the
Transactions, and the Purchaser is willing to do so, but only on the terms and
subject to the conditions set forth in this Consent and Amendment.
<PAGE>

                           A  G  R  E  E  M  E  N  T
                           -  -  -  -  -  -  -  -  -

     NOW, THEREFORE, in consideration of the foregoing and the mutual covenants,
conditions and provisions contained herein, and for other good and valuable
consideration, the receipt and sufficiency of which are hereby acknowledged, the
parties hereby agree as follows:

1.   LIMITED CONSENT TO TRANSACTIONS.
     --------------------------------

     Effective upon the satisfaction of the conditions precedent set forth in
Section 4 below (the first date upon which all of such conditions precedent have
been satisfied is referred to herein as the "Effective Date") and subject to the
                                             --------------
terms and conditions set forth herein, the Purchaser shall be deemed to have
consented to the Transactions.  The consent provided for in this Section 1 shall
be limited solely to the Transactions being entered into as of the Effective
Date, and shall not be construed to apply to any other transaction entered into
by the Company, Parent or Overhill Ventures prior to, simultaneously with or at
any time after the Transactions.

2.   AMENDMENTS TO SECURITIES PURCHASE AGREEMENT.
     --------------------------------------------

     Effective on and as of the Effective Date, and pursuant to Section 12.2 of
the Securities Purchase Agreement, the Securities Purchase Agreement shall be
amended as follows:

     (a) Section 1.1 (Definitions) of the Securities Purchase Agreement is
amended by adding the following new definition to such Section in alphanumerical
order:

         "First Amendment" shall mean a Consent and First Amendment to
          ---------------
     Securities Purchase Agreement dated as of August 23, 2000, among the
     parties."

         "Real Property" shall have the meaning set forth in Section 1.15A of
          -------------                                      -------------
     Annex A."
     -------

         "SSE Asset Purchase Agreement" shall mean the Asset Purchase Agreement
          ----------------------------
     dated as of August 7, 2000, between the Company and SSE Manufacturing.

         "SSE Manufacturing" shall mean SSE Manufacturing, Inc., a California
          -----------------
     corporation, the "Seller" under the SSE Asset Purchase Agreement.

     (b) Section 1.15A (Environmental Matters) of Annex A to the Securities
Purchase Agreement is amended by adding the following new clause (e) to the end
of such Section:
<PAGE>

               "(e) As soon as practicable, but not later than September 1,
         2000, the Company shall retain a qualified environmental engineer
         acceptable to the Purchaser to conduct "Phase II" environmental
         assessment studies of the Real Properties that are subject to the
         leases entered into or assumed by the Company in connection with the
         transactions contemplated by the SSE Asset Purchase Agreement, the
         scope of which environmental assessment studies shall be satisfactory
         to the Purchaser. The Company shall cause such engineer to deliver to
         the Company, as soon as practicable but in any event not later than one
         hundred and twenty (120) days after the Effective Date (as such term is
         defined in the First Amendment), a written report with respect to all
         such Real Properties disclosing its findings, conclusions and
         recommendations. The Company shall also cause such environmental
         engineer to furnish such written report to the Purchaser concurrently
         with its furnishing to the Company. If such report discloses any
         Hazardous Materials Claim or other adverse environmental condition on
         or with respect to any of such Real Properties, or recommends the
         remediation of any Hazardous Materials Claim or other adverse
         environmental condition, the Company shall immediately notify SSE
         Manufacturing in writing of the same and, if SSE Manufacturing is or
         may be liable or otherwise responsible for such Hazardous Materials
         Claim or other adverse environmental condition under the SSE Asset
         Purchase Agreement or otherwise, cause SSE Manufacturing to remediate
         the same in accordance with all Environmental Laws, all at SSE
         Manufacturing's sole cost and expense and to the Company's reasonable
         satisfaction. The parties acknowledge and agree that nothing in this
         Section 1.15A(e) shall negate or otherwise limit any rights of the
         ----------------
         Purchaser or any other obligations of the Company or any Guarantor
         under this Section 1.15A with respect to any Real Property."
                    -------------

     (c) Section 2.1A (Limitations on Indebtedness) of Annex A to the Securities
Purchase Agreement is amended by deleting such Section in its entirety and
replacing it with the following:


         "2.1A  Limitations on Indebtedness. The Company shall not, and shall
                ---------------------------
         not permit any of its Subsidiaries to, create, incur, assume,
         guarantee, suffer to exist or become or remain liable with respect to
         any Indebtedness, except for:

                (a)  Obligations to Purchaser; or

                (b)  Indebtedness payable to the Senior Lender under the Senior
         Credit Documents (excluding any refinancings, restructurings (whether
         in the nature of a "work out" or otherwise), restatements or refundings
         thereof), subject to the limitations and other provisions set forth in
         the Intercreditor Agreement; or
<PAGE>

                (c)  Guaranties constituting the endorsement of negotiable
         instruments for deposit or collection in the ordinary course of
         business; or

                (d)  Trade accounts payable arising in the ordinary course of
         business that are more than sixty (60) days from their due dates, that
         are not being contested in good faith in a commercially reasonable
         manner and that do not exceed $200,000 in the aggregate at any time; or

                (e)  Subordinated Indebtedness payable under that certain
         Unsecured Promissory Note dated August 25, 2000, made payable by the
         Company to SSE Manufacturing in the principal amount of $900,000."

     (d) Section 3.4A (Maximum Capital Expenditures) of Annex A to the
Securities Purchase Agreement is amended by deleting such Section in its
entirety and replacing it with the following:

         "3.4A  Maximum Capital Expenditures.  Capital Expenditures shall not
                ----------------------------
         exceed $400,000 for any Fiscal Quarter, and shall in no event exceed
         $1,200,000 for any Fiscal Year; provided, however, that if (a) the
                                         --------  -------
         Company prepares and furnishes to the Purchaser a "payback" analysis of
         Capital Expenditures it proposes to make or incur in excess of such
         amounts, (b) the Purchaser has at least five (5) Business Days to
         review such analysis and (c) if satisfied with such analysis in its
         sole discretion, the Purchaser consents in writing to such excess
         amount(s) prior to the incurrence thereof, then the Company may make or
         incur such excess Capital Expenditures."

     (e) Schedules 3.7(b), 3.10, 3.12(a)(i) through (vi), 3.13(a), 3.14, 3.20,
3.21, 3.25, 3.26, 3.27, 3.31, 3.35 and 3.36 to the Securities Purchase Agreement
are amended by deleting such Schedules in their entirety and replacing them with
the Schedules included in Exhibit A hereto, each of which Schedules has been
                          ---------
updated on and as of the Effective Date to reflect, among other things, the
transactions contemplated by the SSE Asset Purchase Agreement.

3.   MATERIAL CONTRACTS.
     ------------------

     The parties acknowledge and agree that, for purposes of the Securities
Purchase Agreement and the other Investment Documents, the SSE Asset Purchase
Agreement and the agreements, instruments and other documents contemplated
thereby or related thereto shall be deemed to be Material Contracts.
<PAGE>

4.   CONDITIONS PRECEDENT TO EFFECTIVENESS OF CONSENT.
     ------------------------------------------------

The effectiveness of the Purchaser's consent to the Transactions pursuant to
Section 1 above and the amendments to the Securities Purchase Agreement pursuant
to Section 2 above is subject to the satisfaction of each of the following
conditions precedent:

     (a) Delivery of Certain Documents.  The Purchaser shall have received each
         -----------------------------
of the following documents:

         (i)     Consent and Amendment.  This Consent and Amendment, duly
                 ---------------------
     executed by the Company, Parent and Overhill Ventures, together with
     Exhibit A hereto;
     ---------

         (ii)    SSE Acquisition Documents.  Copies of the final SSE Asset
                 -------------------------
     Purchase Agreement and all related agreements, instruments and other
     documents executed and delivered in connection therewith, duly executed by
     the parties thereto, certified by the Secretary of the Company as being
     true, correct and complete and further certifying that the conditions
     precedent to the consummation of the transactions contemplated by the SSE
     Asset Purchase Agreement have been satisfied (except for those that require
     the effectiveness of this Consent and Amendment and the concurrent funding
     by the Senior Lender of the "Term Loan" contemplated by the Senior Lender
     First Amendment);

         (iii)   Senior Lender Documents. Executed copies of the Senior Lender
                 -----------------------
     First Amendment and the agreements, instruments and other documents
     executed and delivered in connection therewith, certified by the Secretary
     of the Company as being true, correct and complete;

         (iv)    First Amendment to Investor Rights Agreement. An Amendment to
                 --------------------------------------------
     Investor Rights Agreement, in form and substance satisfactory to the
     Purchaser, duly executed by the Company and Parent;

         (v)     First Amendment to Intercreditor Agreement. A First Amendment
                 ------------------------------------------
     to Intercreditor and Subordination Agreement, in form and substance
     satisfactory to the Purchaser, duly executed by the Senior Lender and
     acknowledged by the Company, Parent and Overhill Ventures;

         (vi)    Secretary's Certificate. A Secretary's Certificate of each of
                 -----------------------
     the Company, Parent and Overhill Ventures, in form and substance
     satisfactory to the Purchaser, duly executed by the Secretary and the
     President of each of the Company, Parent and Overhill Ventures,
     respectively, certifying as to the resolutions approving (A) the
     transactions contemplated by the SSE Asset Purchase Agreement, (B) the
     transactions contemplated by the Senior Lender First Amendment and the
     documents relating thereto and (C) the transactions contemplated by this
     Consent and Amendment and the documents relating thereto; and
<PAGE>

         (vii)   Officers' Certificate. An Officers' Certificate, in form and
                 ---------------------
     substance satisfactory to the Purchaser, duly executed by the President and
     the Chief Financial Officer of each of Company, Parent and Overhill
     Ventures, respectively, certifying that (a) after giving effect to the
     Schedules specifically included in Exhibit A to this Consent and Amendment,
     each of the representations and warranties made by the Company and the
     Guarantors in the Securities Purchase Agreement and the other Investment
     Documents is true and correct in all respects as of the Effective Date,
     with the same effect as if made on and as of the Effective Date; and (b) no
     Default or Event of Default shall exist or result from the consummation of
     the Transactions (as such term is defined in the SSE Asset Purchase
     Agreement), the making of the "Term Loan" as contemplated by the Senior
     Lender First Amendment or the execution, delivery or performance by the
     Company or any Guarantor of this Consent and Amendment or the documents
     relating hereto.

     (b) Delivery of Collateral Security Documents.  The Purchaser shall have
         -----------------------------------------
received each of the following documents:

         (i)     UCC-1 Financing Statements, in form and substance satisfactory
     to the Purchaser, duly executed by the Company as debtor, to be filed with
     the Governmental Authorities designated by the Purchaser;

         (ii)    A First Amendment to Patent, Trademark and Copyright Security
     Agreement, in form and substance satisfactory to the Purchaser, duly
     executed by the Company and Overhill Ventures;

         (iii)   Written evidence that the Assets are subject only the Liens
     of the Senior Lender and the Purchaser; and

         (iv)    An Assignment of Representations, Warranties and Covenants in
     favor of the Purchaser, in form and substance satisfactory to the
     Purchaser, duly executed by the Company and consented to by the Seller.

     (c) Landlord Waivers; Tenant Estoppel.  The Purchaser shall have received
         ---------------------------------
(i) landlord waivers and consents, in form and substance satisfactory to the
Purchaser, duly executed by the Company and each landlord/lessor under the real
property leases to be entered into by the Company with respect to (A) 7666
Formula Place, San Diego, CA, (B) 7696 Formula Place, San Diego, CA and (C) 9090
Kenamar Drive, San Diego, CA, and (ii) a tenant estoppel letter, in form and
substance satisfactory to the Purchaser, duly executed by the landlord under the
real property lease to be assumed by the Company with respect to 7666 Formula
Place, San Diego, CA.

     (d) Insurance Coverage.  The Purchaser shall have received written evidence
         ------------------
that the Assets are covered by the Company's insurance policies required to be
maintained in accordance with Section 1.9A of Annex A to the Securities Purchase
Agreement.
<PAGE>

     (e) Environmental Reports.  The Purchaser shall have received true, correct
         ---------------------
and complete copies of Phase I environmental assessment reports with respect to
the parcels of real property that are subject to the real property leases to be
entered into or assumed by the Company in connection with the consummation of
the transactions contemplated by the SSE Asset Purchase Agreement, and such
environmental assessment reports shall be satisfactory to the Purchaser in its
sole discretion.

     (f) Reliance Letter.  The Purchaser shall have received a letter from
         ---------------
Freeman, Freeman & Smiley LLP, special counsel to the Company ("FF&S"),
                                                                ----
authorizing the Purchaser to rely upon the legal opinion letter delivered by
FF&S to the Senior Lender in connection with the transactions contemplated by
the Senior Lender First Amendment.

     (g) Independent Director.  The Purchaser shall have received written
         --------------------
evidence that the Independent Director has been duly elected or appointed to the
Board of Directors of the Company.

     (h) Corporate Proceedings.  All corporate proceedings and legal matters
         ---------------------
taken in connection herewith, with the Senior Lender First Amendment and with
the Transactions shall be satisfactory to the Purchaser and its legal counsel in
their sole discretion.

5.  PAYMENT OF PURCHASER LEGAL FEES.
    -------------------------------

    Within two (2) Business Days following notice from the Purchaser, the
Company shall pay to the Purchaser, or directly to Purchaser's counsel at the
Purchaser's request, all costs and expenses (including attorneys' fees and
disbursements) expended or incurred by or on behalf of the Purchaser in
connection with the Purchaser's investment in the Company Parties and remaining
unpaid, including, without limitation, all attorneys' fees and disbursements
incurred in connection with the preparation, negotiation and execution of this
Amendment and the agreements, instruments and other documents relating hereto or
contemplated hereby and the completion of any post-Effective Date matters.

6.  CONFIRMATION; FULL FORCE AND EFFECT.
    -----------------------------------

    This Consent and Amendment amends the Securities Purchase Agreement on and
as of the Effective Date, and the Securities Purchase Agreement shall remain in
full force and effect as amended hereby in accordance with its terms.  The
Securities Purchase Agreement, as amended hereby, and the other Investment
Documents are hereby ratified and affirmed in all respects.  Nothing herein
shall be deemed to be a waiver of any covenant or agreement contained in, or any
breach, violation, Default or Event of Default under, the Securities Purchase
Agreement or any other Investment Document.  The execution, delivery and
effectiveness of this Consent and Amendment shall not (a) limit, impair,
constitute a waiver by, or otherwise affect any right, power or remedy of, the
Purchaser under the Securities Purchase Agreement or any other Investment
Document or (b) except as specifically set forth in Section 2 of this Consent
and Amendment, alter, modify, amend or in any way affect any of the terms,
conditions, obligations, covenants or agreements contained in the Securities
Purchase Agreement or in any other Investment
<PAGE>

Document, all of which are ratified and affirmed in all respects and shall
continue in full force and effect.

7.  MISCELLANEOUS.
    -------------

    (a) Further Assurances.  The parties hereto shall, at any time and from
        ------------------
time to time following the execution of this Consent and Amendment, execute and
deliver such further instruments and other documents and take such further
actions as may be necessary or appropriate to carry out the provisions of this
Consent and Amendment.

    (b) Governing Law.  In all respects, including all matters of construction,
        -------------
validity and performance, this Consent and Amendment and the rights and
obligations arising hereunder shall be governed by, and construed and enforced
in accordance with, the laws of the State of California applicable to contracts
made and performed in such state, without regard to the choice of law or
conflicts of law principles thereof.

    (c) Successors and Assigns.  This Consent and Amendment shall inure to the
        ----------------------
benefit of, and be binding upon, the parties and their respective successors and
permitted assigns.

    (d) Counterparts.  This Consent and Amendment may be executed in any number
        ------------
of counterparts and by facsimile, each of which shall be deemed an original, but
all of which taken together shall constitute one and the same instrument.



                       [REST OF PAGE INTENTIONALLY BLANK]
<PAGE>

IN WITNESS WHEREOF, the parties have caused this Amendment to be executed and
delivered by their duly authorized representatives as of the first date written
above.


                COMPANY
                -------

                OVERHILL FARMS, INC., a Nevada corporation


                By: _________________________________
                        James Rudis
                        President and Chief Executive Officer


                PARENT
                ------

                POLYPHASE CORPORATION, a Nevada corporation


                By: _________________________________
                        James Rudis
                        President and Chief Executive Officer


                OVERHILL VENTURES
                -----------------

                OVERHILL L.C. VENTURES, INC., a California corporation


                By: ____________________________
                        James Rudis
                        President
<PAGE>

                PURCHASER
                ---------

                LEVINE LEICHTMAN CAPITAL PARTNERS II, L.P.,
                a California limited partnership

                By:  LLCP California Equity Partners II, L.P.,
                     a California limited partnership, its General Partner

                     By:  Levine Leichtman Capital Partners, Inc., its General
                          Partner


                                By: ____________________________
                                        Arthur E. Levine
                                        President
<PAGE>

                 ACKNOWLEDGMENT AND REAFFIRMATION OF GUARANTY
                 --------------------------------------------

     The undersigned Guarantors hereby acknowledge that they have read the
foregoing Consent and Amendment.  The undersigned hereby consent to the Consent
and Amendment, ratify and reaffirm the Guaranty as set forth in Section 9 of the
Securities Purchase Agreement, as amended by the Consent and Amendment, and
acknowledge that the same shall remain in full force and effect in accordance
with it terms.

                GUARANTORS
                ----------

                POLYPHASE CORPORATION, a Nevada corporation


                By: ____________________________________________________
                        James Rudis
                        President and Chief Executive Officer


                OVERHILL L.C. VENTURES, INC., a California corporation


                By: ____________________________________________________
                        James Rudis
                        President
<PAGE>

                                   EXHIBIT A
                                   ---------


                               Updated Schedules



                                   [ATTACHED]