Bogen DB130 power amp conversion
- Thread starter ab0ez
- Start date
ab0ez
AB0EZ
Since the amp has been reconfigured as a pure power amp, all the inputs have been removed and the 12AX7 phono stage amp removed and the 12AU7 tone stage removed. This made for a lot more room underneath. Also, I changed the remaining 12AX7 to a 6CG7. I like the sound of the 6CG7 and the gain of a 12AX7 isn't needed. Here is a shot of the input 6CG7 tube and a Russian .1uF Teflon cap that couples the two stages together. I run the input from the preamp into a 330K terminating resistor. The output of the first half of the 6CG7 is routed through the .1uF cap, to the input level control, and then into the second half of the 6CG7.
A new isolated RCA input jack fit perfectly in the spot vacated by the Aux 1 input level adjust pot. This is connected to the 6CG7 by a short length of Teflon coax.
A new isolated RCA input jack fit perfectly in the spot vacated by the Aux 1 input level adjust pot. This is connected to the 6CG7 by a short length of Teflon coax.
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earphone
Active Member
Thanks for this thread, ab0ez. I'm a newbie here and just acquired a DB-130A on ebay. Haven't even unpacked it yet but am looking forward to getting it up and running. I chanced into a Bogen stereo tube amp in the 80s but it stayed behind when I moved across coast. I believe it was a 230A or DB-212 but I'm not sure. It looked primitive with its simple metal case and plastic knobs but every time I had a party people would freak when they heard how great the music sounded and then caught a glimpse of the prehistoric amp cranking out such sweet loud tunes. I'm far from an audio expert but I think Bogen may be the most underrated tube gear out there.
earphone
Active Member
Actually I just went through your thread again and looked at the pics of the 130 faceplates. The awesome amp I had in the 80s may have been a 130 after all (the silver version). Tomorrow I need to uncrarte my newly acquired amp and check it out.
Also, I had lasik about 9 years ago and never regretted it. Just treat your eyes gently.
No rubbing them. And keep some drops around for those (rare) days when you might want to refesh them (if you're exposed to smoke etc).
Also, I had lasik about 9 years ago and never regretted it. Just treat your eyes gently.
No rubbing them. And keep some drops around for those (rare) days when you might want to refesh them (if you're exposed to smoke etc).
Kiauma
Member
Hello Ab0ez,
I recently procured a pair of DB130's and searching the web I came upon this thread.
Mine are the original type, with the single 5U4G rectifiers, which I now realize isn't the best type, but I am still very interested in modding them for better performance.
I would prefer, however, to maintain their original front end functionality, or as much of it as practicable, to retain some value as 'restorations'. That said, anything else I can do to make them better performers I am all for!
You have obviously done a tremendous amount of research and work, and I really appreciate you offering your hard won knowledge in this thread!
I recently procured a pair of DB130's and searching the web I came upon this thread.
Mine are the original type, with the single 5U4G rectifiers, which I now realize isn't the best type, but I am still very interested in modding them for better performance.
I would prefer, however, to maintain their original front end functionality, or as much of it as practicable, to retain some value as 'restorations'. That said, anything else I can do to make them better performers I am all for!
You have obviously done a tremendous amount of research and work, and I really appreciate you offering your hard won knowledge in this thread!
uncynd
Member
Really missing some of these last few pics that seem to have gone MIA.
Can't wait to perform this. Thoughts on simplifying the rectifier circuit with simply 5V4s vs the 6CG3 damper diode? I'm not sure I understand how to incorporate the 6CG3 or if that endeavor is even worth it?
Thank-you for this thread, it is awesome.
