<PAGE>
 
                                                                   Exhibit 10.33


                               February 26, 1996



Congress Financial Corporation (Northwest)
101 S.W. Main Street, Suite 725
Portland, OR 97204

                    Re:  Twelfth Amendment to Accounts Financing Agreement
                         -------------------------------------------------
 
Ladies and Gentlemen:

          This Twelfth Amendment to Accounts Financing Agreement, dated as of
the 26th day of February, 1996 (this "Amendment") is for the purpose of amending
the Accounts Financing Agreement [Security Agreement] which we entered into on
or about December 20, 1990, as it has been previously amended (the "Accounts
Financing Agreement").

          For valuable consideration, receipt and sufficiency of which are
acknowledged, we agree as follows:

          1.  The first sentence of Paragraph 9.1 of the Accounts Financing
Agreement is amended to provide as follows:

          "9.1  This Agreement shall remain effective and shall continue in
          force and effect for a term ending May 31, 1996 (the "Renewal Date")
          and from year to year thereafter, unless sooner terminated pursuant to
          the terms hereof."

          2.  To induce you to accept this Amendment, we make the following
representations, warranties, and covenants:

          (a)  Each and every recital, representation, and warranty contained in
     this Amendment, the Accounts Financing Agreement, and the Deed of Trust is
     correct as of the date of this Amendment.

          (b)  No event has occurred or is continuing which constitutes or, with
     the giving of notice, the passage of time, or both, would constitute, an
     Event of Default under the Accounts Financing Agreement.

          3.  We shall pay all expenses, including attorney fees, which you
incur in connection with the preparation and implementation of this Amendment
and any related documents.

          4.  Except as specifically provided above, the Accounts Financing
Agreement remains fully valid, binding, and enforceable according to its terms.
<PAGE>
 
Congress Financial Corporation (Northwest)
February 26, 1996
Page 2

          5.  We waive and discharge any and all defenses, claims,
counterclaims, and offsets which we may have against you and which have arisen
or accrued up to the date of this Amendment.  We acknowledge that you and your
employees, agents and attorneys have made no representations or promises to us
except as specifically reflected in this Amendment and in the written agreements
which have been previously executed.  In this connection, we specifically waive
the provisions of California Civil Code (S) 1542, which provides as follows:

          A general release does not extend to claims which the creditor does
          not know or suspect to exist in his favor at the time of executing the
          release, which, if known by him, must have materially affected his
          settlement with the debtor.

                                        Very truly yours,

                                        CARVER CORPORATION


                                        By  /s/ John P. World
                                           --------------------------
                                        Its Executive Vice President
                                           --------------------------
          The undersigned guarantor acknowledges that Congress Financial
Corporation (Northwest) ("Congress") has no obligation to provide it with notice
of, or to obtain its consent to, the terms of this Amendment.  The undersigned
guarantor nevertheless hereby (i) acknowledges and agrees to the terms and
conditions of this Amendment; (ii) acknowledges that its guaranty remains fully
valid, binding and enforceable; and (iii) waives any and all defenses, claims,
counterclaims and offsets against Congress which may have accrued to date.  In
connection with these waivers, the undersigned guarantor specifically waives the
provisions of California Civil Code (S) 1542, which provides as follows:

          A general release does not extend to claims which the creditor does
          not know or suspect to exist in his favor at the time of executing the
          release, which, if known by him, must have materially affected his
          settlement with the debtor.


                                        USS CORPORATION, dba US Sound


                                        By  /s/ John P. World
                                           --------------------------
                                        Its Secretary
                                           --------------------------

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Congress Financial Corporation (Northwest)
February 26, 1996
Page 3


ACCEPTED AND AGREED:

CONGRESS FINANCIAL CORPORATION (NORTHWEST)


By  /s/ Drew Stawin
   --------------------------
Its Vice President
   --------------------------
7267\00026\0118490