FORM OF LINE OF CREDIT NOTE


$1,500,000                                                  September __, 1997
                                                            New York, New York


            SONICS & MATERIALS,  INC., a Delaware  corporation  (the "Company"),
for  value  received,  hereby  promise  to pay to the  order of  BROWN  BROTHERS
HARRIMAN & CO. (the  "Lender") the principal  amount of ONE MILLION FIVE HUNDRED
THOUSAND  DOLLARS  ($1,500,000)  or, if less, the unpaid principal amount of the
Lender's Line of Credit outstanding under the Credit Agreement referred to below
on the dates and in the amounts  provided in the Credit  Agreement.  The Company
also promises to pay interest on the unpaid principal amount hereof from time to
time  outstanding at such rate and on such dates as are  determined  pursuant to
the Credit  Agreement.  The Company also  promises to pay interest on the unpaid
principal  amount hereof from time to time  outstanding at such rate and on such
dates as are determined pursuant to the Credit Agreement. All such principal and
interest  shall be  payable in lawful  money of the United  States of America in
same day funds at the office of the Lender.

            This  Note is the Line of  Credit  Note  referred  to in the  Credit
Agreement  dated of even date  herewith  (the  "Credit  Agreement")  between the
Company  and the Lender and is  entitled to the  benefits  thereof.  Capitalized
terms used but not defined  herein  have the  meanings  specified  in the Credit
Agreement.

            The date and  amounts of each  Advance  under the Line of Credit and
each  repayment  and  prepayment  of principal  thereof,  may be endorsed by the
Lender on the schedule  attached  hereto,  or on a continuation of such schedule
attached to and made a part  hereof.  The failure to make or any error in making
any such  endorsement  shall not  limit,  extinguish  or in any way  modify  the
Company's  obligations  under the  Credit  Agreement  or this  Note,  including,
without limitation, the obligation of the Company to repay the Lenders's Line of
Credit, together with interest thereon, strictly in accordance with the terms of
the Credit Agreement and this Note.

            This Note is subject to  prepayment  and its  maturity is subject to
acceleration upon the terms provided in the Credit Agreement.

            The Company hereby waives presentment,  demand, protect or notice of
any kind in connection with this Note.

            THIS NOTE SHALL BE GOVERNED BY AND CONSTRUED IN ACCORDANCE  WITH THE
LAWS OF THE STATE OF NEW YORK.

                              SONICS & MATERIALS, INC.


                              By:   __________________________________-
                                    Name:
                                    Title:


<PAGE>


                                   Schedule


            Principal         Payments or
Date        Amount            Prepayments of          Balance     Notation
of Loan     of Loan           Principal                     Outstanding Made
By


<PAGE>


                              LINE OF CREDIT NOTE


$1,500,000                                                  September __, 1997
                                                            New York, New York


            SONICS & MATERIALS,  INC., a Delaware  corporation  (the "Company"),
for  value  received,  hereby  promise  to pay to the  order of  BROWN  BROTHERS
HARRIMAN & CO. (the  "Lender") the principal  amount of ONE MILLION FIVE HUNDRED
THOUSAND  DOLLARS  ($1,500,000)  or, if less, the unpaid principal amount of the
Lender's Line of Credit outstanding under the Credit Agreement referred to below
on the dates and in the amounts  provided in the Credit  Agreement.  The Company
also promises to pay interest on the unpaid principal amount hereof from time to
time  outstanding at such rate and on such dates as are  determined  pursuant to
the Credit  Agreement.  The Company also  promises to pay interest on the unpaid
principal  amount hereof from time to time  outstanding at such rate and on such
dates as are determined pursuant to the Credit Agreement. All such principal and
interest  shall be  payable in lawful  money of the United  States of America in
same day funds at the office of the Lender.

            This  Note is the Line of  Credit  Note  referred  to in the  Credit
Agreement  dated of even date  herewith  (the  "Credit  Agreement")  between the
Company  and the Lender and is  entitled to the  benefits  thereof.  Capitalized
terms used but not defined  herein  have the  meanings  specified  in the Credit
Agreement.

            The date and  amounts of each  Advance  under the Line of Credit and
each  repayment  and  prepayment  of principal  thereof,  may be endorsed by the
Lender on the schedule  attached  hereto,  or on a continuation of such schedule
attached to and made a part  hereof.  The failure to make or any error in making
any such  endorsement  shall not  limit,  extinguish  or in any way  modify  the
Company's  obligations  under the  Credit  Agreement  or this  Note,  including,
without limitation, the obligation of the Company to repay the Lenders's Line of
Credit, together with interest thereon, strictly in accordance with the terms of
the Credit Agreement and this Note.

            This Note is subject to  prepayment  and its  maturity is subject to
acceleration upon the terms provided in the Credit Agreement.

            The Company hereby waives presentment,  demand, protect or notice of
any kind in connection with this Note.

            THIS NOTE SHALL BE GOVERNED BY AND CONSTRUED IN ACCORDANCE  WITH THE
LAWS OF THE STATE OF NEW YORK.

                              SONICS & MATERIALS, INC.


                              By:   __________________________________-
                                    Name:
                                    Title:


<PAGE>


                                   Schedule


            Principal         Payments or
Date        Amount            Prepayments of          Balance     Notation
of Loan     of Loan           Principal                     Outstanding Made
By