Document:

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                                                                     EXHIBIT 4.1

                      AMENDMENT TO NOTE PURCHASE AGREEMENT
                            AND SENIOR DISCOUNT NOTES

     This Amendment to Note Purchase Agreement and Senior Discount Notes (this
"Amendment") dated as of May 30, 2001 is by and among Ampex Data Systems
Corporation (the "Issuer"), Ampex Corporation (the "Guarantor"), the entities
identified as "Purchasers" on the signature pages hereto (the "Purchasers"), and
DDJ Capital Management LLC (the "Holders' Agent").

     WHEREAS, the Issuer, the Guarantor, the Purchasers and the Holders' Agent
are parties to a certain Note Purchase Agreement dated as of November 6, 2000
(the "Note Purchase Agreement") with respect to $8,919,555.56 aggregate
principal amount of Senior Discount Notes due May 31, 2001 of Ampex Data Systems
Corporation; and

     WHEREAS, in accordance with the terms of the Note Purchase Agreement, the
Issuer issued to the Purchasers on November 7, 2000 Senior Discount Notes due
May 31, 2001 in the aggregate principal sum of $8,919,555.56 (the "Senior
Discount Notes"); and

     WHEREAS, pursuant to a letter agreement dated as of November 6, 2000 (the
"Letter Agreement"), the Issuer, the Guarantor and the Holders' Agent
acknowledged and agreed that (i) the Senior Discount Notes were actually issued
on November 7, 2000, and (ii) the Accreted Value of the Senior Discount Notes as
of any date would be calculated as if the "Issue Date" of the Senior Discount
Notes was November 7, 2000 rather than November 6, 2000 as contemplated by the
Note Purchase Agreement; and

     WHEREAS, the Issuer and the Guarantor have requested that the Purchasers
and the Holders' Agent agree to amend the Note Purchase Agreement and the Senior
Discount Notes to extend the stated maturity date of the Senior Discount Notes
from May 31, 2001 to August 31, 2001; and

     WHEREAS, the Purchasers and the Holders' Agent are willing to amend the
Note Purchase Agreement and the Senior Discount Notes to extend the stated
maturity date of the Senior Discount Notes on the terms and subject to the
conditions set forth herein;

     NOW THEREFORE, in consideration of the mutual covenants and agreements
set forth herein and for other good and valuable consideration, the receipt and
sufficiency of which are hereby acknowledges, the parties hereto do hereby agree
as follows:

     1. Capitalized terms used herein without definition shall have the meaning
set forth in the Note Purchase Agreement.

     2. Notwithstanding anything to the contrary set forth in the Note Purchase
Agreement, the Notes or the Letter Agreement, the parties hereto do hereby agree
that:

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               (a) The Senior Discount Notes shall mature and be due and payable
          in full on the earliest to occur of (i) August 31, 2001, (ii) a
          Mandatory Redemption Date, or (iii) a Designated Voluntary Redemption
          Date (the earliest to occur of any of the foregoing being hereinafter
          referred to as the "Redemption Date");

               (b) On June 1, 2001, the Senior Discount Notes shall be deemed to
          have an Accreted Value of $1,000 per $1,000 principal amount of Senior
          Discount Notes;

               (c) The Senior Discount Notes shall cease to accrete in value
          from and after June 1, 2001 and instead, from June 2, 2001 through the
          Redemption Date, interest shall accrue on the unpaid Accreted Value of
          the Senior Discount Notes at a rate of twenty percent (20%) per annum,
          compounding on April 30th and October 31st of each year, and based on
          an annual period of twelve 30-day months, which interest shall be due
          and payable in full in cash on the Redemption Date; provided that if
          for any reason the interest or other amounts payable in respect of the
          Senior Discount Notes or otherwise under the Note Purchase Agreement
          are found by a court of competent jurisdiction, in a final
          determination, to exceed the limit which may be lawfully charged, then
          the obligation of the Issuer to pay interest and other charges shall
          automatically be reduced to such limit and, if any amount in excess of
          such limit shall have been paid, then such amount shall be refunded to
          the Issuer; and

               (d) If the Issuer fails to pay to the Holders of the Senior
          Discount Notes on or before the Redemption Date cash in an amount
          equal to the sum of (A) the Accreted Value of the Senior Discount
          Notes as of June 1, 2001, and (B) accrued and unpaid interest on such
          Accreted Value as set forth above in Section 2(c) of this Amendment,
          interest shall accrue on the unpaid portion of the Accreted Value of
          the Senior Discount Notes (and on the unpaid portion of accrued
          interest) at the Default Rate for each day from and after the
          Redemption Date until the entire Accreted Value of the Senior Discount
          Notes and all accrued interest thereon, shall have been paid in full.

     3. The Guarantor hereby acknowledges, confirms, ratifies and agrees that
(i) pursuant to the provisions of Article XIV of the Note Purchase Agreement,
the Guarantor has guaranteed the obligations of the Issuer under the Note
Purchase Agreement and the Senior Discount Notes, (ii) as security for the
obligations of the Issuer and the Guarantor under the Note Purchase Agreement,
the Guarantor has granted to the Holders' Agent for the benefit of the Holders,
pursuant to the Collateral Security Agreement, a security interest in all of the
right, title and interest now owned or hereafter acquired by the Guarantor in
various royalties, license fees, receivables and other payment, and (iii) the
Note Purchase Agreement and the Collateral Security Agreement are presently and,
after giving effect to this Amendment, will continue to be valid and binding
obligations of the Guarantor enforceable in accordance with their respective
terms.

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     4. This Amendment shall become effective on the date that each of the
following conditions has been fulfilled to the satisfaction of the Holders'
Agent, provided that any or all of the following conditions may be waived, in
whole or in part, by the Holders' Agent in its sole discretion:

               (a) The Issuer, the Guarantor, the Purchasers and the Holders'
          Agent shall have executed and delivered to the Holders' Agent an
          original of this Amendment; and

               (b) The Issuer and the Guarantor shall have executed and
          delivered to the Holders' Agent such additional documents as the
          Holders' Agent may reasonably request, including, without limitation,
          (i) an Amendment to the Colorado Deed of Trust, (ii) an updated
          certificate of insurance naming the Holders' Agent as Additional
          Insured and Loss Payee under the policies with respect to the Colorado
          Facility, and (iii) a letter agreement from Hillside Capital
          Corporation extending Hillside Capital Corporation's `waiver of its
          right to obtain a mortgage on the Colorado Facility until the
          thirtieth (30th) day following the extended maturity date of the
          Senior Discount Notes, each of which additional documents shall be in
          form and substance reasonably satisfactory to the Holders' Agent.

     5. Each of the Issuer and the Guarantor further covenant and agree to
deliver to the Holder's Agent as soon as practicable but in any event no later
than June 30, 2001 (i) a recorded copy of an Amended and Restated Memorandum of
Right of First Refusal correcting the legal description of the portion of the
vacant land comprising the Colorado Facility that is the subject of a right of
first refusal in favor of US Filters, and (ii) a copy of an executed amendment
to the Real Estate Purchase Agreement between the Guarantor and US Filters
reflecting the corrected legal description of the portion of the vacant land
comprising the Colorado Facility that is the subject of a right of first refusal
in favor of US Filters.

     6. Each of the Issuer and the Guarantor acknowledges, represents and
warrants that neither the Issuer nor the Guarantor has any claim, cause of
action, defense, or right of set off against the Purchasers or the Holders'
Agent, and, to the extent that either the Issuer or the Guarantor has any such
rights, each of the Issuer and the Guarantor hereby releases, waives, and
forever discharges the Purchasers and the Holders' Agent (together with their
predecessors, successors and assigns) from each action, cause of action, suit,
debt, defense, right of set off, or other claim whatsoever, in law or in equity,
known or unknown against the Purchasers or the Holders' Agent.

     7. This Amendment may be executed in counterparts, each of which shall be
an original and all of which shall constitute one and the same agreement.

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     8. This Amendment shall be governed and construed in accordance with the
laws of The Commonwealth of Massachusetts. If any provision of this Agreement is
in conflict with a statute or rule of the law of The Commonwealth of
Massachusetts, or is otherwise unenforceable for any reason whatsoever, such
provision shall be deemed null and void to the extent of such conflict or
unenforceability, but shall be deemed separable from and shall not invalidate
any other provisions of this Amendment.

     9. This Amendment contains the final, complete, and exclusive expression of
the understandings between the parties regarding the transaction contemplated by
this Amendment.

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     IN WITNESS WHEREOF, each of the undersigned parties through their
authorized representatives has executed and delivered this Amendment as an
instrument under seal as of the date set forth above.

                           "ISSUER"

                           Ampex Data Systems Corporation

                           By: /s/ Craig L. McKibben
                               -------------------------------------------------
                               Name:  Craig L. McKibben
                               Title:    Vice President

                           "GUARANTOR"

                           Ampex Corporation,

                           By: /s/ Craig L. McKibben
                               -------------------------------------------------
                               Name: Craig L. McKibben
                               Title:  Vice President

                           "PURCHASERS"

                           B III Capital Partners, L.P.
                           By:  DDJ Capital III, LLC, its General Partner
                           By:  DDJ Capital Management, LLC, Manager

                           By: /s/ David J. Breazzano
                               -------------------------------------------------
                               Name: David J. Breazzano
                               Title:  Member

                           B III-A Capital Partners, L.P.
                           By:  GP III-A, LLC, its General Partner
                           By:  DDJ Capital Management, LLC, Manager

                           By:  /s/ David J. Breazzano
                               -------------------------------------------------
                               Name: David J. Breazzano
                               Title:  Member

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                              State Street Bank & Trust, solely in its capacity
                              as Custodian for General Motors Employees
                              Global Group Pension Trust as directed by be DDJ
                              Capital Management, LLC, and not in its
                              individual capacity

                                By: /s/ Andrew Hood
                                    --------------------------------------------
                                    Name: Andrew Hood
                                    Title: Assistant Secretary

                              "HOLDERS' AGENT"

                              DDJ Capital Management,
                              LLC, in its capacity as
                              Agent for the Purchasers
                              and the other holders from
                              time to time of Senior
                              Discount Notes

                                By: /s/ David J. Breazzano
                                    ------------------------------------------
                                    Name: David J. Breazzano
                                    Title: Member<PAGE>
                                                                     EXHIBIT 4.2

                               FIRST AMENDMENT TO
                               ------------------
                       DEED OF TRUST, SECURITY AGREEMENT,
                       ----------------------------------
                             FINANCING STATEMENT AND
                             -----------------------
                        ASSIGNMENT OF RENTS AND REVENUES
                        --------------------------------

     THIS FIRST AMENDMENT TO DEED OF TRUST, SECURITY AGREEMENT, FINANCING
STATEMENT, AND ASSIGNMENT OF RENTS AND REVENUES (this "Amendment") is entered
into as of the 30th day of May, 2001, by and among Ampex Data Systems
Corporation, a Delaware corporation, whose legal address is 500 Broadway,
Redwood City, California 94063-3199, together with any future owner of the
Property or any part thereof or interest therein (the "Grantor") and DDJ Capital
Management, LLC, as Holders' Agent under the Note Purchase Agreement (defined
below) for the Holders defined therein, together with any future holder of the
Notes (defined below) (the "Beneficiary"). Capital terms used herein without
definition shall have the meanings given to them in the Deed of Trust (defined
below).

     WHEREAS, the Grantor, Ampex Corporation, as guarantor (the "Guarantor"),
the Holders, and Beneficiary, as agent for the Holders, are parties to that
certain Note Purchase Agreement dated as of November 6, 2000 (the "Original Note
Purchase Agreement"), pursuant to which Grantor issued its Senior Discount Notes
in the aggregate principal amount of $8,919,555.56 (the "Original Senior
Discount Notes");

     WHEREAS, pursuant to that certain Deed of Trust, Security Agreement,
Financing Statement and Assignment of Rents and Revenues dated as of November 6,
2000 from Grantor to The Public Trustee of El Paso County, Colorado (the
"Trustee") for the benefit of the Beneficiary, and recorded with the El Paso
County, Colorado recorders office on November 8, 2000 at reception number
200135916 (the "Original Deed of Trust");

     WHEREAS, the Grantor, the Guarantor, the Holders and the Beneficiary are
parties to that certain Amendment to Note Purchase Agreement and Senior Discount
Notes, of even date herewith (the "Note Purchase Amendment"), pursuant to which
the Original Note Purchase Agreement (as amended by the Note Purchase Amendment,
the "Note Purchase Agreement") and the Original Senior Discount Notes (as
amended by the Note Purchase Agreement, the "Senior Discount Notes") have been
amended to extend the stated maturity date of the Senior Discount Notes; and

     WHEREAS, the Grantor and Beneficiary wish to amend the Original Deed of
Trust in accordance with the terms and provisions set forth herein (the Original
Deed of Trust as amended by this Amendment, the "Deed of Trust").

     NOW THEREFORE, in consideration of the mutual covenants and agreements set
forth herein and for other good and valuable consideration, the receipt and
sufficiency of which are hereby acknowledged, the Grantor and the Beneficiary do
hereby agree as follows:

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          1. Section 1.4 of the Deed of Trust is hereby deleted in its entirety
and the following substituted therefor:

          1.4 Notes: Collectively, the Grantor's Senior Discount Notes (as
defined in the Note Purchase Agreement) in the maximum principal amount of
$8,919,555.56 and more particularly described therein and in the Note Purchase
Agreement, as amended by the Note Purchase Amendment, together with all
renewals, extensions, and modifications of the Notes, issued by Grantor in
accordance with the terms and conditions of the Note Purchase Agreement, and any
note delivered in substitution or exchange for any such note. All terms and
provisions of the Notes are incorporated by this reference in this Deed of
Trust.

          2. Section 1.5 of the Deed of Trust is hereby deleted in its entirety
and the following substituted therefor:

          1.5 Note Purchase Agreement: The Note Purchase Agreement dated as of
November 6, 2000, by and among Grantor, Ampex Corporation, a Delaware
corporation, as guarantor thereunder (the "Guarantor"), the purchasers listed on
the signature pages thereto (collectively, the "Holders"), and Beneficiary, as
agent for the Holders, as amended by the Note Purchase Amendment dated as of May
30, 2001, together with all renewals, extensions, and modifications of the Note
Purchase Agreement; pursuant to which Grantor has issued the Notes made payable
to the Holders and Guarantor, as owner of all of the issued and outstanding
capital stock of the Grantor, has guaranteed the obligations of the Grantor
under the Notes and the Note Purchase Agreement.

          3. As amended hereby, the Deed of Trust is ratified and confirmed and
shall remain in full force and effect.

          4. This Amendment may be executed in any number of counterparts, each
of which counterparts shall be deemed to be an original, and such counterparts
shall constitute but one and the same Amendment.

          5. The Grantor's Federal Tax Identification Number is 94-3112575.

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                  Signed and delivered as of the date first mentioned above.

                              GRANTOR:       AMPEX DATA SYSTEMS CORPORATION

                                             By: /s/ Craig L. McKibben
                                               ---------------------------------
                                               Name: Craig L. McKibben
                                               Title: Vice President

                              BENEFICIARY:   DDJ CAPITAL MANAGEMENT LLC

                                             By: /s/ David J. Breazzano
                                               ---------------------------------
                                               Name: David J. Breazzano
                                               Title: Member

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