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                                                                     Exhibit 8.1




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                                  June 3, 1999


To the Addressees listed
  on Schedule I hereto

                  Re:     Advanta Mortgage Loan Trust 1999-2
                          Mortgage Loan Asset-Backed Certificates, Series 1999-2
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Ladies and Gentlemen:

                  We have acted as special tax counsel in connection with the
issuance and delivery of certain mortgage loan asset-backed certificates
denominated Advanta Mortgage Loan Trust 1999-2, Mortgage Loan Asset-Backed
Certificates, Series 1999-2 (collectively, the "Certificates"), pursuant to a
Pooling and Servicing Agreement dated as of May 1, 1999 (the "Pooling and
Servicing Agreement") among Advanta Mortgage Conduit Services, Inc. ("Conduit
Services"), Advanta Mortgage Corp. USA, as Master Servicer (the "Master
Servicer") and Bankers Trust Company of California, N.A., as trustee (the
"Trustee").

                  As special tax counsel, we have examined such documents as we
deemed appropriate for the purposes of rendering the opinions set forth below,
including the following: (a) Prospectus dated May 6, 1999 (the "Prospectus"), a
Preliminary Prospectus Supplement dated May 21, 1999 (the "Preliminary
Prospectus Supplement") and a Prospectus Supplement dated May 26, 1999 (the
"Prospectus Supplement") with respect to the Class A Certificates, and (b) an
executed copy of the Pooling and Servicing Agreement and the exhibits attached
thereto.

                  Terms capitalized herein and not otherwise defined herein
shall have their respective meanings as set forth in the Pooling and Servicing
Agreement.

                  Based upon the foregoing and upon the assumptions set forth
below, we are of the opinion, under the laws of the United States, New York
State, New York City and California in effect as of the date hereof, that:

                  1. Assuming that (a) each of the Upper-Tier REMIC and the
Lower-Tier REMIC created under the Pooling and Servicing Agreement elects, as it
has covenanted to do in the Pooling and Servicing Agreement, to be treated as a
"real estate mortgage investment conduit" ("REMIC"), as such term is defined in
the Internal Revenue Code of 1986, as amended (the "Code") and (b) the parties
to the Pooling and Servicing Agreement comply with the terms thereof, both the
Upper-Tier REMIC and the Lower-Tier REMIC will be treated as REMICs. Subject to
the above, (i) the Lower Tier REMIC Regular Interests, each Class of Class A
Certificates and the Class B Certificates issued pursuant to the Pooling and
Servicing Agreement will be treated as one or more "regular interests" in the
related REMIC and (ii) the Class R Certificates and Class RL Certificates will
be treated as the sole "residual interest" in the related REMIC.


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                  2. The statements under the caption "CERTAIN FEDERAL INCOME
TAX CONSEQUENCES" in the Prospectus, the Preliminary Prospectus Supplement and
the Prospectus Supplement and "STATE TAXES" in the Preliminary Prospectus
Supplement and the Prospectus Supplement are accurate and complete in all
material respects.

                  3. As a consequence of the qualification of the Upper-Tier
REMIC and the Lower-Tier REMIC each as a REMIC, the Class A Certificates will be
treated as "regular . . . interest(s) in a REMIC" under Section 7701(a)(19)(C)
of the Code and "real estate assets" under Section 856(c) of the Code in the
same proportion that the assets in the Trust consist of qualifying assets under
such Sections. In addition, as a consequence of the qualification of the
Upper-Tier REMIC and the Lower-Tier REMIC each as a REMIC, interest on the Class
A Certificates will be treated as "interest on obligations secured by mortgages
on real property" under Section 856(c) of the Code to the extent that such Class
A Certificates are treated as "real estate assets" under Section 856(c) of the
Code.

                  4. The Trust will not be subject to tax upon its income or
assets by the taxing authority of New York State or New York City.

                  5. The Trust will not be subject to the California state
income tax. While REMICS are subject to the California state minimum franchise
tax imposed under Article 2, Section 23153 of the California Revenue and
Taxation Code, no opinion is expressed as to whether the Trust is subject to
such tax.

                  6. Neither the Trust nor any portion thereof, including,
without limitation, the Supplemental Interest Account, will be treated as an
association taxable as a corporation for federal income tax purposes.

                  7. The acquisition, in the manner contemplated by the Pooling
and Servicing Agreement, by the Trust from time to time during the Pre-Funding
Period of the Subsequent Mortgage Loans will not cause either the Upper-Tier
REMIC or the Lower-Tier REMIC to fail to qualify as a REMIC, nor will any such
acquisition result in either the Lower-Tier REMIC or the Upper-Tier REMIC
engaging in a "prohibited transaction" under Section 860F(a) of the code.


                                             Very truly yours,
                                             /s/ Dewey Ballantine LLP