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Bogen DB230A?

jon_s

jon_s

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I just got one of these off eBay -- the one that uses 6AV5GA sweep tubes. It seems to be a bit of an "oddball" amp (possibly a sleeper?), and I figured it would be fun to restore.

... SO, does anyone have a pdf or gif schematic? :scratch2: images.google hasn't been helpful for this one.

I'm guessing the front end is pretty standard -- 12AX7 phono and tone, with 7199 gain+splitter -- but it has a random 6CM7 that I'm hoping might be a regulator for the screens.
 
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I had a DB230A and it used 6DW5 output tubes - 9-pin miniatures, and I recall the DB230 did as well. The mono DB-130 did use the 6AV5. Your guess was correct - the 6CM7 is the screen regulator.

I have the Sams folder for the DB230 (not the A) - email for a scan. Rectifiers are different - don't know what else might be. Sams 524-6 covers the 230A - but the Bogen manual would be nice to have.
 
Hmmm $7.99 isn't too bad at all. I'll take a look at the unit to see how intuitively laid-out it is -- I may be able to get by without.

So how did the 6DW5 Bogen sound? I have seen those for sale too, but wanted to try a 6AV5 model since the tubes are so cheap and available. Looks like a solid amp in construction, but I guess the real question will be the OPTs.
 
I have one of these sitting for some months now, waiting for restoration (it is a working unit but I want to replace old caps mainly for safety reason). It has a lot of components though, compared to other amps. And a lot of caps to replace. Mine has a not-so-nice faceplate, with several letters cancelled, but I fear that finding a better looking replacement is very very difficult.
 
Raul said:
I have one of these sitting for some months now, waiting for restoration (it is a working unit but I want to replace old caps mainly for safety reason). It has a lot of components though, compared to other amps. And a lot of caps to replace. Mine has a not-so-nice faceplate, with several letters cancelled, but I fear that finding a better looking replacement is very very difficult.
Click to expand...

There ARE a lot of components in there! I just got the schematic, and it seems the power supply is dual mono for all stages past the output B+. And, the small signal tubes all have DC filaments. I think I can re-do the power supply with a pair of JJ 40/20/20/20's, one 32/32, plus some Solen 8uF films for phono stage bypass. It's going to take a ton of small caps too, as the existing Good-Alls are likely All-Bads. Overall a pretty neat amp -- if it ends up sounding good, at least.
 
Just finished this amp last night at bricktop's place. Wanted to post a shot of it up'n running! Really sounds great so far -- I look forward to hearing it on my speakers.
 

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To anybody who has one of these and hasn't tried it yet -- I strongly advise taking the time to restore it! Major sleeper alert!

Connected to AR 302s, as long as I don't go nuts with the volume control, this sounds almost exactly like my Citation I and II combo (admittedly minus some bass and balls). The phono stage is fantastic, the amp is dead quiet, and it has no trouble driving the 4 ohm speakers on the 8 ohm taps. I will hook it up modern speakers and report back...

...OK, back! Verdict: Still sweet :) Quite neutral and transparent, fantastic imaging, but somehow still warm and friendly. None of that colored tube technicolor sound -- very natural.
 
Sorry misters, i need a bogen diagram circuit or service manual for the 'A' VERSION.
I just see if is possible change socket in the output for use another tubes.
Best Regards
Esteban Bikic
dady@comodoro.com
 
Thanks jon_s i just buy one by ebay. I didn't open this audiokarma for long time and i had the solution here. Just i found the project. Anyway thanks for your reliable information.
 
No, never used 3rd channel. I didn't keep it long - tested it to spec and sold it. I would have kept it if it used 6AV5s - have plenty of hose for spares.
 
You sure you didn't have db230? Haha. Alot to these things. Still figuring out 6 months later. We all try to improve right?
 
Well almost 20 years ago... I could be wrong. I might have some photos of it - on my desktop computer which is 600 miles from here.
 
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