<PAGE>

                               SUBLEASE AGREEMENT

        This Sublease Agreement (the 'Sublease') is entered into by and between
Ambord Corporation, a California corporation ('Sublessor') and Hauppauge Record
Manufacturing Company, a New York corporation, and its parent company, Allied
Digital Technologies, a Delaware corporation, (hereinafter referred to jointly
and severally as 'Sublesse').

                                    Recitals

         A.       Sublessor is presently the lessee of the Premises pursuant to 
the Master Lease. A copy of the Master Lease is attached to this Sublease as
Exhibit A and incorporated into by this reference.

         B.       Sublessor desires to sublease the Premises to Sublessee and 
Subleasee desires to sublease the Premises from Sublessor, subject to the terms,
covenants, and conditions set forth below.

         C.       Sublessor leases to Subleasee and sublessee hires from 
Sublessor the following described together with the appurtenances, situated at
480 Valley Dr. in the City of Brisbane, County of San Mateo, State of
California: a free standing single story 22,160 square foot building located on
Industrially zoned Assessors Parcel Number 005-241-160 consisting of
approximately 54,896 square feet of improved land (hereafter referred to as 'the
premises').

                                    AGREEMENT

         NOW, THEREFORE, in consideration of the foregoing, the parties agree as
follows:

         1. Sublease. Sublessor hereby subleases to Sublessee, and Subleasee
hereby subleases from Sublessor, the Premises for the Term, and upon all of the
terms, covenants and conditions as set forth in the Master Lease and in
accordance with the entire remaining term thereof- eleven (11) years and one (1)
month. Except as provided herein, the terms and conditions of the Master Lease
shall apply to the parties hereto.

         2. Condition of Premises/Inspections. Sublessor shall deliver to
Sublessee the premises with professionally cleaned carpets, restrooms sanitized
and the warehouse broom swepted. Sublessee shall be solely responsible for
conducting any inspections it may deem necessary or appropriate in determining
whether to enter this Sublease. Subleases may, prior to the Effective Date,
conduct an investigation of the Premises and the physical condition thereof,
including accessibility and location of utilities, improvements, existence of
hazardous materials, including but not limited to asbestos, asbestos containing
materials, polychlorinated biphenyls (PCB), and underground tanks which in
Sublesse's judgment might affect or influence Sublessee's use of the Premises or
Sublessee's willingness to enter into this Sublease. Except for the seismic
condition of the building, Sublessee subleases the Premises to Sublessee on an
"AS IS BASIS", and Sublessee acknowledges that except for the disclosure letter
dated March 26, 1997, Sublessor has made no representations of any kind in

connection with soils, improvements, or physical conditions on, or bearing on,
the use of the Prerm@ses, whether express or implied. Sublessee further
acknowledges and agrees that neither Sublessor nor Lewor shall be required to
perform any work of construction, alteration or maintenance of or to the
Premises.

         3. Sublease Subject to Master Lease.

                  a.       Inclusions. This Sublease shall be subject to, and 
there shall be incorporated herein by reference, all of the terms, covenants and
conditions of the Master Lease, except as excluded in Section 4.b. below and
except to the extent such terms, covenants and conditions conflict with the
provisions of this Sublease, in which case the provisions of this Sublease shall
govern and control. It is understood and agreed that the term 'Lessee,' as used
in the Master Lease refers to 'Sublessee' hereunder, and, subject to Section 5
of this Sublease, the term 'Lessor' shall refer to 'Sublessor' hereunder.
Sublessee shall assume all of the obligations and perform all of the duties of
Sublessor as lessee under the Master Lease with respect to the Premises.
Sublessee shall not commit or permit to be committed any act or omission which
shall violate any terms, covenants or conditions of the Master Lease. An event
of default under the Master Lease shall constitute an event of default
hereunder, and Sublessor may exercise any or all remedies provided for in the
Master Lease against Sublessee in such an event, including, but not limited to,
termination hereof.

                  b.       Exclusions.  The terms and provisions of the 
following sections and portions of the Master Lease are not incorporated into
the Sublease:

                           (1)      Base Rent.  Beginning on July 1, 1997, the 
sublessee shall pay to Sublessor as provided herein and further defined in
Paragraph 4.1 of the Master Lease, the Base Rent of Thirteen Thousand Two
Hundred and Ninety Six Dollars ($13,296.00 or $.60 per square foot) for the
balance of the initial year and through to November 30, 1998. Thereafter the
Base Rent shall be increased as provided in Section 1.5.1 of the Master Lease
Addendum.

                           (2)      Rate Adaustments.  The Base Rent Adjustments
of the sublease shall be as defined Section 1.5.1 of the Master Lease Addendum,
with the additional provision at each Adjustment Date

<PAGE>

defined therein, that each adjustment shall be capped at a maximum of six
percent (6%) and a minimum of two percent (2%) annually but effective every
three (3) years.

                             (3)    Lessees Right of First Refusal.  If 
Sublessor does not indicate it's agreement to purchase Premises as provided in
Section 49 of the Master Lease, Sublessor shall give notice to Sublessee of the
terms Lessor is willing to sell premises within eight (8) days of receipt of
such notice. Sublessee shall have eight (8) days of receipt of Sublessor's
notice to indicate it's agreement to purchase. Lessor shall thereafter have the
right to see the Premise as provided in the Master Lease, Section 49.


                    C. Time for Notice. The time limits provided for in the
provisions of Master Lease for the giving of notice, making of demands,
performance of any act, condition or covenant, or the exercise of any right,
remedy or option, are amended for the purposes of this Sublease, by lengthening
or shortening the same in each instance by five (5) days, as appropriate, so
that notices may be given, demands made, or any act, condition or covenant
performed, or any right, remedy or option hereunder exercised, by Sublessor or
Sublessee, as the case may be, within the time limit specified in the Master
Lease. If the Master Lease allows five (5) days or less for Sublessor to perform
any act, or to undertake to perform such act, or to correct any failure relating
to the Premises or this Sublease, then Sublessee shall nevertheless be allowed
three (3) days to perform such act, undertake such act and/or correct such
failure, except with respect to Section 3.b(3) hereof.

           4.     Use.  The Premises shall be used in accordance with the Master
Lease, and for no other purpose or business.

           5.     Assignment and Subletting. Any assignment of this Agreement or
sublease of the Premises shall be in accordance with the provisions of the
Master Lease, and Sublessor agrees that it will not unreasonably withhold
consent as required by the Master Lease.

           6. Repairs and Maintenance. Except as to any material costs or
compliance with any requirement to seismically upgrade the premises, Sublessee
shall keep the Premises in safe condition, and in good order and repair at all
times during the Term at Sublessee's sole cost and expense. Sublessee shall, at
Sublessee's sole expense, repair any area damaged by Sublessee, Sublessee's
agents, employees and visitors. Sublessee acknowledges that Sublessor is under
no duty to make repair or improvements to the Premises. At the end of the Term,
Sublessee shall surrender to Sublessor the Premises and all alterations thereto
in the same condition as when received, ordinary wear and tear and damage by
fire, earthquake, act of God or the elements excepted.

           7.     Insurance Policies; Indemnification.

                    a.     Sublessee's Insurance Policies. During the Term,
Sublessee shall procure and maintain in full force and effect and at Sublessee's
sole cost and expense the following policies of insurance. All policies of
insurance required to be maintained by Sublessee hereunder shall name Sublessor
and Lessor as additional insureds and shall be issued by insurance companies
approved by Sublessor. In the event the premium for any policy required
hereunder is increased by reason of any act or omission of Sublesm or its
general partners, agents or employees, Sublessee shall be responsible to pay
when due, as Additional Rent, such increases.

                    (1)    Liability. A policy or policies of comprehensive 
general liability insurance, insuring Sublessee's activities and those of
Sublessee's employees, agents, licensees and invitees with respect to the
Premises against loss, damage or liability for personal injury or death of any
person or loss or damage to property occurring on the Premises or as a result of
occupancy of the Premises, with a limit of not less than those provided for in
the Master Lease.


                             (2)    All Risk and Extended Coverage of 
Sublessee's Improvement and Property. A policy or policies of all risk property,
and extended coverage insurance in an amount equal to one hundred percent (100%)
of the full insurance replacement value (without deduction for depreciation) of
Sublessee's leasehold improvements and any alterations thereto, trade fixtures,
equipment, merchandise, and other personal property.

                             (3)    Workers' Compensation and Employees' 
Liabilities. A policy or policies of workers compensation and employee liability
insurance in adequate amounts as required by law.

                    b.     Fire and Extended Coverage of Building.  Sublessor 
shall obtain and maintain complete fire and extended coverage insurance as
required under the Master Lease.

                    C.     Waiver of Subrogation. Any policy or policies of 
fire, extended coverage or similar casualty insurance which either party obtains
in connection with the Promises, shall, to the extent the same can be obtained,
include a clause or endorsement denying the insurer any rights of subrogation
against the other party. Sublessee and Sublessor hereby waive any rights of
recovery against the other for injury or loss due to hazards covered by fire,
extended coverage or similar casualty insurance, which either party obtains in
connection with the Premises, to the extent of the injury or loss covered
thereby and so long as the aforsaid waiver of subrogation is in effect, or to
the extent such injury or loss would have been covered and such waiver of
subrogation would have been in effect if such insurance and clause had been
obtained as required hereunder.

                                      -2-

<PAGE>

d.                  Insurance Certifirates. Sublessee shall fumish to Sublessor
a certificate of insurance issued by the insurance carrier of each policy of
insurance required to be obtained by Sublessee hereunder upon the Effective Date
aad thereafter within thirty (30) days prior to the expiration of any policy
required to be maintained by Section 14(a) above. Each such certificate shall
expressly provide that the policy evidenced thereby shall not be cancelled,
subject to reduction of coverage or otherwise modified except after (30) days
prior written notice to all parties named as insureds therein.

                    e.     Indenmifiration of Sublessor. Sublessee shall 
indemnify, defend by counsel acceptable to Sublessor, and hold Sublessor and
their employees, agents and any other person acting on their behalf harmless
from and against any and all liabilities, penalties, losses, damages, costs and
expenses, demands, causes of action, claims or judgments arising out of or in
connection with any injury to persons or damage to property occurring (1) in, on
or about the Premises; (2) as a result of any accident or other occurrence
occasioned by an act or omission of Sublessee, Sublessee's officers, employees,
agents, servants, subtenants, concessionaires, contractors or visitors; (3)
during Sublessee's term from the use, maintenance, occupation or operation of
the Premises, including the use, presence, disposal, storage, generation or
release of any `hazardous materials,' 'hazardous substances,' 'hazardous wastes'
or 'toxic substances' as those terms may be defined in any federal, state or

local legislation currently existing or enacted in the future; (4) any breach or
default by Sublessee of any of the terms, covenants or conditions on its part to
be observed or performed under this Sublease; and/or (5) all legal costs and
charges, including reasonable attomey's fees, in connection with such matters
and the defense of any action arising out of the same or in discharging the.
Premises from any and all liens, charges or judgments which may accrue or be
placed thereon by any reason of any act or omission of Sublessee. The provisions
of this Section 14(d) shall survive the expiration or earlier termination of
this Sublease. To the extent of any occupancy of the premises by Sublessor after
the date hereof, Sublessor agrees to hold harmless, defend and indemnify
Sublessee from and against any liability arising from such occupancy.

           8.     Default and Remedies. This Agreement shall be subject to the 
same default and remedy provision contained in the Master Lease.

         10.      Miscellaneous.

                    a.     Notices.  All notices, requests, or demands or 
payments of any kind required or desired to be given hereunder shall be in
writing and shall be deemed to be delivered on the date of delivery if
personally served, or forty-eight (48) hours after being deposited in the United
States mail, certified or registered, postage prepaid, return receipt requested
(unless return receipt indicates not delivered) and addressed to Sublessor at
Sublessor's Address.

                    b.     Time.  Time is of the essence of this Sublease.

                    c.     Entire Aereement. This Sublease contains all of the
terms, covenants and conditions between the parties concerning the Premises and
shall supersede all prior correspondence, agreements and understanding
concerning the Promises, both oral and written. No addition or modification of
any term or provision of this Sublease shall be effective unless set forth in
writing and signed by both Sublessor and Sublessee.

           d.     Successors and Assigns.  Subject to the provisions of this 
Sublease and the Master relating to assigmment, mortgaging and subletting, this
Sublease shall bind the heirs. executors, administrators, successors and assigns
of any and all of the parties hereto.

                    e.     Authority. Each individual executing this Sublease on
behalf of Sublessee represents and warrants that he or she is duly authorized to
execute and deliver this Sublease on behalf of Sublessee, and that this Sublease
is binding upon Sublessee in accordance with its terms. Sublessor, as a
condition precedent to this Sublease, may require corporate or partnership
resolutions as are reasonably necessary to establish the authority of Sublessee
to execute this Sublease.

                    f.     Attorneys' Fees. If any party commences an action or
arbitration proceeding against the other party arising out of or in connection
with this Sublease, the prevailing party shall be entitled to re--over from the
losing party the cost and expenses of such action, including reasonable
attorneys' fees and court and arbitration costs.

                    g.     Governing Law.  This Sublease shall be governed by 

and construed in accordance with the laws of the State of California.

                    h.     Captions.  All captions and headings in this Sublease
are for the purposes of reference and convenience and shall not limit or expand
the provisions of this Sublease.

                                      -3-

<PAGE>

                    i.     Counterparts.  This Sublease may be entered into in 
counterparts. each of which shall be deemed an original but both of which
together shall be deemed a single agreement.

j.       Brokers.   The following real estate brokers and brokerage 
relationships exist relative to this Sublease transaction and are consented to
by the parties and any commissions related to same will be paid by the
responsible parties in accordance with the terms and conditions of separate
agreements between Sublessor and Sublessee, respectively, as well as BT
Commercial, M.V.P. Management and Grubb & Ellis, as the case may be.

         11.      Consent of Lessor.  This agreement is subject to the prior 
written consent of San Bruno Associates, Lessor on the Master Lease, accordance
with the attached Consent.

Dated                                   Dated:

Sublessor                               Sublessees

Ambord Corporation                      Hauppauge Record Manufacturing Company, 
                                        a New York corporation

By                                      By

Address:   P.O. Box 619'                Address:    140 Fell Ct.
           Orinda, CA 94563                         Hauppauge, NY 11788
           (415) 467-4500                           (516) 232-2323



                                        Allied Digital Technologies,
                                        a Delaware corporation

                                          By --.

                                        Address:    140 Fell Ct.
                                                    Hauppauge, NY 11788
                                                    (516) 232-2323

                                       4-

<PAGE>

                               SUBLEASE AGREEMENT

                                SUMMARY OF TERMS

Term:                               Eleven (11) years and one (1) month in 
                                    accordance with the Master Lease.

Sublessor:                          Ambord Corp.

Sublessor's Address:                P.O. Box 619
                                    Orinda, CA 94563

Sublessee:                          Hauppauge Record Manufacturing Company
                                    Allied Digital Technologies

Sublessee's Address:                140 Fell Ct.
                                    Hauppauge, NY 11788

Premises:                           Sublessor leases to Sublessee and Sublessee
                                    hires from Sublessor the following described
                                    together with appurtenances, situated at 480
                                    Valley Dr. in the City of Brisbane, County
                                    of San Mateo, State of California: a free
                                    standing single story 22,160 square, foot
                                    budding located on industrially zoned
                                    Assessors Parcel Number 005-241-160
                                    consisting of approximately 54,886 square
                                    feet of improved land.

Permitted Uses:                     any lawful use

Base Rent:                          $13,296 plus adjustments

Occupancy Date:                     June 1, 1997

Rental Commmencement Date:          July 1, 1997

Security Deposit:                   None

Master Lease:                       Dated December 1, 1993 by and between Ambord
                                    Corporation and San Bruno Associates

Lessor:                             San Bruno Associates

Lessor's Address:                   1ll Pine Street
                                    San Francisco, CA

Effective Date:                     Upon mutual execution of Sublease

Expiration Date:                    June 30, 2008, as provided in the Master 
                                    Lease

<PAGE>

                              Addendum to Sublease


                               Dated April 21,1997
                                 for premises at
                       480 Valley Dr., Brisbane California

This Addendum to Sublease dated April 21, 1997, is entered into by and between
Ambord Corporation, A California Corporation ('Sublessor') and Hauppauge Record
Manufacturing Company, a New York Corporation, and it's parent company Allied
Digital Technologies, a Delaware Corporation (hereinafter referred to jointly
and severally as "Sublessee").

      3.b. (1) a. Additional Rent:

The Base Rent shall be increased by Two and One-half cents ($.02.5) per square
foot bringing the total Base Rent to Thirteen Thousand Eight Hundred and Fifty
Dollars ($13,850.00 or $.62.5 per square foot) for the term of the Sublease for
Sublessee's purchase from Sublessor of an additional 600 amp electrical power
box as required delivered a minium of six (6) weeks from the date requested, the
Steelcase panel systems with surfaces and pedestals which are completely set-up
with electrical power and phone lines, and the existent Pac-Tel Series 100 phone
system and intercom system. This increase of Base Rent will commence on January
1, 1998, and continue through the term of the Sublease subject to the provisions
in the Master Lease and 3.b.(2) of the Sublease.

SUBLESSOR                                SUBLEESSEES

AMBORD CORPORATION,                      HAUPPAUGE RECORD,
a California corporation                 MANUFACTURING COMPANY,
                                         a New York corporation

  By                                     By

  Name:                                  Name:Charles Kavanagh

  Title:                                 Title: Executive Vice President
Address:     P.O.Box 619                 Address:    140 Fell Ct-
             Orinda, Ca. 94563                       Hauppauge, NY 11788
             (415) 467-4500                          (516) 232-2323

Date:                                    Date:-  May 29, 1997

                                         ALLIED DIGITAL TECHNOLOGIES,
                                         a Delaware corporation

                                         By
                                         Name: Charles Kavanagh

                                         Title:   Executive Vice President
                                         Address:    140 Fell Ct.
                                                     Hauppauge, NY 11788
                                                     (516) 232-2323

                                         Date: -May 29, 1997

LANDLORD.


SAN BRUNO ASSOCIATES,
A California General Partnership

By

Name:

Title:

<PAGE>

Address:          111 Pine St. Suite 1250
                  San Francisco, Ca. 94111
                  (415) 990-0490
Date: