For the Dimensional diagram and hookup sheet for this unit please click here (Adode Acrobat Reader required) PA135 replacement power transformer for Dynaco (tm) Mark 4. Bolts directly on without modifications. Rated 370-0-370V (740VCT) at 150 ma, 5V at 3A, 6.3VCT at 4.5A, also has 55V bias tap. Primary 117VAC 60 Hz. Brand new production, MADE IN USA. It is possible to use the PA135 as a general replacement power transformer in other amps (or DIY projects) that put out 35 to 50W from a pair of 6550's or EL34's. Sunn Replacement Part# 3-4PT PA135 Dynaco Mk IV Power Transformer Replacement also for Sunn 3-4PT MADE IN USA pa135$102.95 END BELL REPLACEMENT COVER FOR PA135 endbellpa135$9.95 Triode, USA For Customer Service, Questions, Shipping, Ordering, etc., M-F 9AM-4PM CT 1-800-774-3201 Email us Anytime: questions@triodestore.com TECH SUPPORT is available 4 days per week: 9 AM to 4 PM CT Monday, Tuesday, Thursday & Friday Ph 1-800-774-3201 Or email: tech@triodestore.com