Exhibit 10.37

NINTH AMENDMENT AND WAIVER TO CREDIT AGREEMENT

NINTH AMENDMENT AND WAIVER TO CREDIT AGREEMENT (this "Amendment"), dated as of January 31, 2002, among ELGAR HOLDINGS, INC. ("Holdings"), ELGAR
ELECTRONICS CORPORATION (the "Borrower"), the lenders party to the Credit Agreement referred to below (the "Banks"), and BANKERS TRUST COMPANY, as Agent (in such capacity, the "Agent"), and
acknowledged by and, to the extent set forth below, agreed to by, J.F. LEHMAN EQUITY INVESTORS I, L.P. ("JFLEI"). All capitalized terms used herein and not otherwise defined herein shall have the
respective meanings provided such terms in the Credit Agreement referred to below.

W I T N E S S E T H:

WHEREAS, Holdings, the Borrower, the Banks and the Agent are parties to a Credit Agreement, dated as of February 3, 1998, and amended and restated as of
May 29, 1998 (as amended, modified or supplemented to, but not including, the date hereof, the "Credit Agreement");

WHEREAS,
JFLEI previously has entered into the JFLEI Cash Collateral Agreement and the JFLEI Guaranty in favor of the Agent, the Collateral Agent and the Banks;

WHEREAS,
the parties hereto wish to amend and/or waive certain provisions of the Credit Agreement as herein provided;

WHEREAS,
concurrently with the effectiveness of this Amendment, JFLEI will enter into in favor of the Agent, the Collateral Agent and the Banks (i) a Guaranty, dated as of
January 31, 2002 (as
amended, modified or supplemented from time to time, the "JFLEI II Guaranty") and (y) a Cash Collateral Agreement, dated as of January 31, 2002 (as amended, modified or supplemented from
time to time, the "JFLEI II Cash Collateral Agreement"); and

WHEREAS,
subject to the terms and conditions of this Amendment, the parties hereto agree as follows.

NOW,
THEREFORE, it is agreed:

1.    Holdings,
the Borrower, the Banks and the Agent hereby acknowledge and agree that (i) on the Ninth Amendment Effective Date (as defined below), the Total Revolving
Loan Commitment shall be increased from $5,000,000 to $6,700,000 (as such amount may be reduced from time to time and/or terminated in accordance with the terms of the Credit Agreement) and
(ii) the initial incurrence of any Revolving Loans pursuant to such increase in the Total Revolving Loan Commitment may be made on February 1, 2002 only and the proceeds from such
initial incurrence may be used solely for the purposes described in the second sentence of Section 7.08(a) of the Credit Agreement (as amended hereby). In connection therewith,
Schedule I of the Credit Agreement is hereby amended by deleting the amount "$5,000,000" appearing each place under the "Revolving Loan Commitment" column appearing therein and inserting in
lieu thereof the amount "$6,700,000".

2.    Section 1.08(d)
of the Credit Agreement is hereby deleted and the following new Section 1.08(d) is inserted in lieu thereof:



1

---



3.    Sections
3.01(a), (b) and (c) of the Credit Agreement are each hereby amended by deleting the words "quarterly in arrears on each Quarterly Payment Date"
appearing in each such Section and inserting the words "monthly in arrears on each Monthly Payment Date" in lieu thereof in each such Section.

4.    Section 3.01
of the Credit Agreement is hereby amended by inserting the following new clauses (g), (h), (i) and (j) at the end thereof:



5.    The
table appearing in Section 4.02(b) of the Credit Agreement is hereby amended by deleting the Scheduled Repayment dates and the corresponding Scheduled
Repayment amounts from and after

2

---

January 30, 2002 and inserting the following new Scheduled Repayment date and Scheduled Repayment amount in lieu thereof in such table:

"Final
Maturity Date                              $8,750,000".

6.    Section 7.08(a)
of the Credit Agreement is hereby amended by inserting the following new sentence at the end thereof:



7.    Section 8.01(f)
of the Credit Agreement is hereby amended by deleting the text "Sections 8.01(b) and (c)" appearing therein and inserting the text "Sections
8.01(a), (b) and (c)" in lieu thereof.

8.    The
text of Section 9.07 of the Credit Agreement is hereby deleted and the following new text is inserted in lieu thereof:

"Intentionally
omitted."

9.    The
text of Section 9.08 of the Credit Agreement is hereby deleted and the following new text is inserted in lieu thereof:

"Intentionally
omitted."

10.    Section 9.09
of the Credit Agreement is hereby deleted and the following new Section 9.09 is inserted in lieu thereof:



Fiscal Month
Ending Closest To

AmountFebruary 28, 2002

$
175,000March 31, 2002

$
340,000April 30, 2002

$
600,000May 30, 2002

$
1,170,000




11.    Section 9
of the Credit Agreement is hereby further amended by inserting the following new Section 9.16 at the end thereof:



12.    Section 10.04
of the Credit Agreement is hereby amended by deleting the amount "$3,000,000" appearing therein and inserting the amount "$150,000" in lieu thereof.

3

---

13.    Section 10.09
of the Credit Agreement is hereby amended by deleting the amount "$2,500,000" each place such amount appears therein and inserting the amount
"$150,000" in lieu thereof in each such place.

14.    The
definition of "Consolidated EBITDA" appearing in Section 11.01 of the Credit Agreement is hereby amended by (i) deleting the word "and" appearing at
the end of clause (x)(ii) thereof and inserting a comma in lieu thereof and (ii) inserting the following new clause (x)(iv) immediately after
clause (x)(iii) thereof:



15.    The
definition of "Credit Documents" appearing in Section 11.01 of the Credit Agreement is hereby amended by inserting the text "the JFLEI II Guaranty,"
immediately after the text "the JFLEI Guaranty," appearing therein.

16.    The
definition of "Credit Party" appearing in Section 11.01 of the Credit Agreement is hereby amended by inserting the following new text at the end thereof:

"and,
for purposes of Sections 10.02 and 10.03, JFLEI".

17.    The
definition of "Final Maturity Date" appearing in Section 11.01 of the Credit Agreement is hereby deleted and the following new definition of "Final Maturity
Date" is inserted in lieu thereof:

"Final
Maturity Date" shall mean June 28, 2002."

18.    The
definition of "Guarantor" appearing in Section 11.01 of the Credit Agreement is hereby amended by inserting the text ", JFLEI (for purposes of
Section 10.08)" immediately after the word "Holdings" appearing therein.

19.    The
definition of "Guaranty" appearing in Section 11.01 of the Credit Agreement is hereby amended by inserting the text ", the JFLEI II Guaranty" immediately
after the text "the JFLEI Guaranty" appearing therein.

20.    The
definition of "Security Document" appearing in Section 11.01 of the Credit Agreement is hereby amended by inserting the text ", the JFLEI II Cash Collateral
Agreement" immediately after the text "the JFLEI Cash Collateral Agreement" appearing therein.

21.    The
definition of "Test Period" appearing in Section 11.01 of the Credit Agreement is hereby deleted and the following new definition of "Test Period" is inserted
in lieu thereof:



22.    Section 11.01
of the Credit Agreement is hereby further amended by inserting the following new definitions in the appropriate alphabetical order:



4

---



23.    The
parties hereto hereby acknowledge and agree that, notwithstanding anything to the contrary contained in any Credit Document, the occurrence of any event of the type
described in Section 10.05 of the Credit Agreement with respect to JFLEI or the general partner thereof shall constitute an immediate Event of Default under the Credit Agreement.

24.    The
Banks hereby waive any Default or Event of Default that has arisen solely as a result of Holdings and the Borrower failing to comply with
(i) Section 9.08 of the Credit Agreement during the period from the last day of Holdings' fiscal quarter ended closest to September 30, 2001 through and including
January 31, 2002 and (ii) Sections 9.07 and 9.09 of the Credit Agreement for the Test Periods ended on the last day of Holdings' fiscal quarters ended closest to September 30,
2001 and December 31, 2001.

25.    The
Credit Agreement is hereby further amended by attaching as "Schedule XIV" thereto the Schedule XIV attached to this Amendment.

26.    Holdings
and the Borrower hereby agree that, at the request of the Agent, they will use their commercially reasonable efforts to promptly obtain control agreements, in
form and substance reasonably satisfactory to the Agent, from those institutions, and with respect to those accounts, listed on Schedule XIV to the Credit Agreement (as amended hereby).

27.    Each
of Holdings and the Borrower acknowledges and agrees that, both before and after giving effect to this Amendment, the guaranties and the security and other
interests granted to the Agent, the Collateral Agent and the other Secured Creditors pursuant to the Credit Documents to which each respective Credit Party is a signatory shall remain outstanding and
in full force and effect in accordance with the Credit Documents, and shall continue to support and secure the Obligations, and that the guaranties and the security and other interests granted to the
Agent, the Collateral Agent and the other Secured Creditors are hereby ratified, confirmed and continued by execution and delivery hereof. The Credit Documents shall, both before and after giving
effect to this Amendment, remain extant and in full force and effect, and each of the Credit Parties hereby ratifies and confirms its respective obligations thereunder. The Borrower hereby
acknowledges that, as of the Ninth Amendment Effective Date (but before giving effect to this Amendment), principal in the amount of $13,750,000, plus accrued and unpaid interest and applicable fees
and expenses, is outstanding under the Credit Agreement, and further acknowledges its unconditional liability to pay such amounts (as well as all Obligations incurred or owing from and after the Ninth
Amendment Effective Date) in accordance with the terms and conditions of the Credit Agreement, all without offset, defense or counterclaim except to the extent expressly set forth in
Section 4.04(b) of the Credit Agreement.

28.    JFLEI
acknowledges and agrees that, both before and after giving effect to this Amendment, the guaranties and the security and other interests granted to the Agent, the
Collateral Agent and the other Secured Creditors pursuant to the JFLEI Guaranty and the JFLEI Cash Collateral Agreement shall remain outstanding and in full force and effect in accordance with such
Credit Documents, and shall continue to support and secure the Guaranteed Obligations (as defined in the JFLEI Guaranty), and that the guaranties and the security and other interests granted to the
Agent, the Collateral Agent and the other Secured Creditors are hereby ratified, confirmed and continued by execution and delivery hereof. The JFLEI Guaranty and the JFLEI Cash Collateral Agreement
shall, both before and after

5

---

giving effect to this Amendment, remain extant and in full force and effect, and JFLEI hereby ratifies and confirms its obligations thereunder.

29.    In
addition to acknowledging and, to the extent provided herein, agreeing to the other provisions of this Amendment, JFLEI hereby acknowledges and agrees that
(i) its obligations under the JFLEI Guaranty and the JFLEI Cash Collateral Agreement are separate and independent of its obligations under the JFLEI II Guaranty and the JFLEI II Cash Collateral
Agreement, (ii) for clarification purposes, the JFLEI Guaranty is hereby amended by inserting the words "under this Guaranty" immediately after the words "Guaranteed Obligations" appearing in
clauses (x) and (y) of the proviso to the first sentence of Section 1 of the JFLEI Guaranty, and (iii) the JFLEI Guaranty is hereby further amended by (a) inserting
the text "and the last sentence of this Section 1" immediately after the words "subject to the limitations set forth in clause (x) of the proviso of the immediately preceding sentence"
appearing in the second sentence of Section 1 of the JFLEI Guaranty and (b) inserting the following new sentence at the end of Section 1 thereof:



30.    This
Amendment shall become effective on the date (the "Ninth Amendment Effective Date") when (i) each of Holdings, the Borrower, JFLEI and the Banks shall have
signed a counterpart hereof (whether the same or different counterparts) and shall have delivered (including by way of facsimile transmission) the same to the Agent at the Notice Office,
(ii) JFLEI shall have executed and delivered (including by way of facsimile transmission) to the Agent at the Notice Office a signed counterpart of each of the JFLEI II Guaranty and the JFLEI
II Cash Collateral Agreement and shall have deposited with the Collateral Agent at least $1,700,000 in cash in accordance with the terms of the JFLEI II Cash Collateral Agreement, (iii) the
Agent shall have received true and correct copies of resolutions duly approved by the board of directors of Holdings and the Borrower with respect to the transactions contemplated by this Amendment,
which resolutions shall be in form and substance reasonably satisfactory to the Agent and shall be certified by the Secretary or an Assistant Secretary of each such Credit Party, (iv) the Agent
shall have received true and correct copies of resolutions duly approved by the managing members of the general partner of JFLEI with respect to the transactions contemplated by this Amendment, the
JFLEI II Guaranty and the JFLEI II Cash Collateral Agreement, which resolutions shall be in form and substance reasonably satisfactory to the Agent and shall be certified by an authorized officer of
JFLEI or the general partner thereof, and (v) the Agent shall have received an opinion from Gibson, Dunn & Crutcher LLP, in form and substance reasonably satisfactory to the Agent, with
respect to the transactions contemplated by this Amendment, the JFLEI II Guaranty and the JFLEI II Cash Collateral Agreement.

31.    In
order to induce the Banks to enter into this Amendment, each of Holdings and the Borrower hereby represents and warrants that (i) no Default or Event of
Default exists on the Ninth Amendment Effective Date, after giving effect to this Amendment, (ii) as of the Ninth Amendment Effective Date and before giving effect to this Amendment, Holdings
and its Subsidiaries may incur at least $1,000,000 of additional Indebtedness in reliance on clause (xiv) of the definition of "Permitted Indebtedness" contained in the Senior Note Indenture
and (iii) the transactions contemplated by this

6

---

Amendment, the JFLEI II Guaranty and the JFLEI II Cash Collateral Agreement do not violate or contravene the Senior Note Indenture or constitute a default or an event of default thereunder.

32.    This
Amendment may be executed in any number of counterparts and by the different parties hereto on separate counterparts, each of which counterparts when executed and
delivered shall be an original, but all of which shall together constitute one and the same instrument. A complete set of counterparts shall be delivered to Holdings, the Borrower and the Agent.

33.    THIS
AMENDMENT AND THE RIGHTS AND OBLIGATIONS OF THE PARTIES HEREUNDER SHALL BE CONSTRUED IN ACCORDANCE WITH AND GOVERNED BY THE LAW OF THE STATE OF NEW YORK.

34.    From
and after the Ninth Amendment Effective Date, all references in the Credit Agreement and each of the other Credit Documents to the Credit Agreement shall be deemed
to be references to the Credit Agreement as modified hereby.

35.    This
Amendment is limited as specified and shall not constitute a modification, acceptance or waiver of any other provision of the Credit Agreement or any other Credit
Document.

*
* *

7

---

IN
WITNESS WHEREOF, each of the parties hereto has caused a counterpart of this Amendment to be duly executed and delivered as of the date first above written.

| |  | ELGAR HOLDINGS, INC.                           
| |  | -----------------------------------------------
| |  | By:                                            
| |  | ELGAR ELECTRONICS CORPORATION                  
| |  | By:                                            
| |  | BANKERS TRUST COMPANY,Individually and as Agent
| |  | By:                                            



|Acknowledged, and as to paragraphs 28 and 29 only, Agreed to, as of the date written above: |  |                                   |  | 
|------------------------------------------------------------------------------------------- |  | --------------------------------- |  | 
|J.F. LEHMAN EQUITY INVESTORS I, L.P.                                                        |  |                                   |  | 
|By: J.F.L. Investors, L.L.C., its sole general partner                                      |  |                                   |  | 
|By:                                                                                         |  | /s/DONALD GLICKMANManaging Member |  | 

8

---

QuickLinks