Old school Bogen Tube PA (viable Guitar amp?)

tubetapexfmr · Post by **tubetapexfmr** » Fri Aug 22, 2008 4:49 pm

Oh, man what a cool idea for converting a turntable! Now I have to go out and find me one of those guys to make a fake leslie with.

Scodiddly · Post by **Scodiddly** » Fri Aug 22, 2008 6:08 pm

jessemesasavage wrote:Oh, man what a cool idea for converting a turntable! Now I have to go out and find me one of those guys to make a fake leslie with.

It's actually more difficult than it looks - that animated .gif is sped up a bit. With max 78 RPM you're looking at a tremelo speed barely above 1Hz. I did see one guy's approach of aiming the speaker down into a coffee can with multiple holes to get a faster tremolo, and my own idea is to make a sort of layer cake of baffles to get a setup where there are three 120-degree openings to effectively sextuple the 78RPM.

Michael.E · Post by **Michael.E** » Fri Aug 22, 2008 6:34 pm

Scodiddly wrote:I had an old Bogen mixer/amp tube thing I bought years ago, and eventually transformed into a frankenstein Fender/Marshall 50 watt amp. I don't play loud guitar often, so I loaned it to a friend who still hasn't given it back. That was around 10 years ago.

One of these days I need to get back to that Bogen tube turntable/amp thing I acquired from my antique dealer cousin a few years back. That thing sounded great for leads, but I spent more time on the similar product from Califone because the turntable still works.

Lately I've been thinking about building a real rotor (Leslie style) for that turntable.

that's awesome! I know those old califone tube amp/record players well..
I still use my solidstate rheem califone tape machine for lofi and crackly leads.
sounds like super compressed/built in speaker and a hacked sound.. it's the champ.

Dubious · Post by **Dubious** » Sat Aug 23, 2008 8:42 am

jessemesasavage wrote:
my main practice amp is a 20 watt McGohan head thru a 4 x 10 cab
Is it the model M204? I have one of those and I can tell you whatever you want to know about it. First of all it is almost identical in design to the Bogen CHB-35A.

i think it is, same tube layout as my Bogen.

I dont want to touch the Mcgohan, bought it from a guy who mods these PA amps on ebay. So its already tweaked perfectly, tone is absolutely incredible. My fave amp by far.

The Bogen on the other hand is def a beater - and on my list to mod

tubetapexfmr · Post by **tubetapexfmr** » Sat Aug 23, 2008 10:30 am

I dont want to touch the Mcgohan, bought it from a guy who mods these PA amps on ebay. So its already tweaked perfectly, tone is absolutely incredible. My fave amp by far.

I search for McGohans on ebay all the time but I have never seen any modified ones. DO you have a name or other info for this guy? I am curious what he does and how much he charges. Since you've got your McGohan I'd say apply my advice on making a badass amp and just apply it to the Bogen CHB-35A. I am just waiting on some tone pots to finish mine and then I'll be able to show you guys what it is capable of.

Jesse

Dubious · Post by **Dubious** » Sat Aug 23, 2008 1:05 pm

the fellow i bought it from sells under the name 211 amps

he doesnt list alot of stuff. He's very meticiulous. This amp was from a stereo pair. IMMACULATE. Cleanest point to point wiring, all bent wires, just gorgeous. He recaps, voices the channels (blendable too) and i think messes with the EQ to make it more guitar friendly. I think i paid $120 for the amp. The matching one closed around $200 something.

I'm VERY interested in what you're doing to the challenger.

tubetapexfmr · Post by **tubetapexfmr** » Sat Aug 23, 2008 4:54 pm

the fellow i bought it from sells under the name 211 amps

Aha, I have seen that guy before. He sounds pretty good. Did it come with the input transformers for that price? If so that is a steal. The transformers alone are worth that much each! Did you know those green octal plug-in transformers are made by Peerless? It is the same inside as the Altec 4722. I think it is model MC-1 and has 50 ohm and 200 ohm input taps. There is also a blue MC-2 that I think is a Peerless as well, but I am not sure. The blue one only has the 200 ohm tap but may actually be the same transformer inside. I don't feel like tearing mine apart to find out. They sound the same to me so that is all the proof I need. Anyhow if you have either of these transformers they make great mic inputs for tube pres or step-up transformers for Moving Coil Vinyl pickups.

I'm VERY interested in what you're doing to the challenger.

Yeah, I am finding a lot of interest with these Bogens, especially the common CHB-35As. They seem to be everywhere! You will love the posting I put up about it once I am done with it. I am waiting on parts until the middle of next week, but by then I should have something to show!

Dubious · Post by **Dubious** » Mon Aug 25, 2008 2:18 pm

yeah this amp came with the transformers, i was wondering if they were the same as the ones for the old altecs.

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Old school Bogen Tube PA (viable Guitar amp?)

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