Motown Direct Amplifier-inspired Preamp?

GroupDIY Audio Forum

Help Support GroupDIY Audio Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
(very similar-looking (earlier?) unit with a different layout)

There's also a top of chassis pic (I've brightened it since the can cap is difficult to make out in the original) :View attachment 137423

[(very similar-looking (earlier?)] -- Your photo of this chassis more accurately follows the drawing posted earlier than the other photo I had used in my Post #433.

1727593096982.png

>> Is it possible for you to provide a list of Part Numbers of the other transformers (i.e., HAMMOND 157G, CineMag CM-????, etc.), the large electrolytic capacitors and anything else used inside the chassis? That would prove to be highly useful with my trying to recreate the mechanical design details of this chassis. NOTE: I basically -- assumed -- the chassis height as being 1.50" high. Can you confirm what the actual chassis height is??? THANKS!!!

/
 
Last edited:
Nice one midnight. I have been using ChatGPT to find out what tubes are used. It says the first three (from left to right in your chassis) are EF86, 12AX7, 12B4A

It gets confused about the fourth tube (the rectifier). First it says it is a 6X4 (which is a small B7G tube), then it says it used a semiconductor rectifier, and lastly it thinks it is a 5AR4/GZ34 (which seems most likely).

The mains transformer (rear right of the chassis) seems to be a Hammond 309JX if my reading is right. Output transformer is a Cinemag and probably physically identical to their CM-2810 model.

Cheers

Ian
FYI:

1727602340230.png
/
 
Back
Top