These amplifiers were built to very high standards in the mid to late 1950's by Allen Organ, inc. in Macungie, Pennsylvania and were recently removed from Allen Organs to be replaced by smaller solid state amplifiers. The construction of these is very solid, as they weigh 55lbs each! The chassis has a ~17"x10" footprint and are around 8" tall. They are capable of 75 watts rms each (when balance and bias are properly adjusted) mono into 4-, 8-, or 16-ohms. Each mono amp uses a pair of 6550's, two 6SN7's, a EF86 phase splitter, and a 12AT7 preamp tube (12AX7 and 12AY7 seem to work fine too). Their power supplies are incredibly robust, using a 15-pound power transformer (compare that to the Dynaco 3lb jobs!) and a large potted inductor. They use early solid state rectification, which should probably be replaced with more reliable modern units (e.g. 1N5404) for better performance. The Model 75's have dual inputs with dual gain controls, a balance adjust on the front and a bias adjust located between the 6550 tubes. They also have two handy test probe sockets for checking the balance with a VOM. These amps do run quite warm (and were designed to), so I like to have a small fan near by. They use a 5A SB main power fuse and a 3/4A SB on the high voltage. They have a short (~18") non-polarized power cord and no on/off switch (reversing the position of the power plug can reduce hum since one side is capacitively coupled to the chassis). They are rated to draw 2.2A nominal (115v) and have serial numbers. These amps have a fabulous reputation for longevity. The Allen Organ repairman from whom I aquired these said he has seen them go untouched since installation in 1960 and still run strong 40 years later (no tubes replaced or anything)!! He has also spotted a similar model to this one for sale at a high profile shop in NY for $900!

• Click on the above images to get more details on each amplifier. Items with an ebay number are currently being auctioned on ebay.
• The shipping for one of these amps is quite tricky. They require very careful and sturdy packing, not to mention the 60-something pound resulting package that must be shipped, so the shipping cost is not negligible. I visited UPS.com and estimated $75 by ground service, or $140 by 3-day. The cost will probably be a little less if you live in the north-east USA.

Serious bidders only, please; bidders who do not follow through with the deal will receive negative feedback. Buyer pays shipping from South East PA (19341), all sales are final. I can accept money orders, cashiers checks, or bank checks. Feel free to contact me for more information: cdanjo@aol.com.