Use for Vintage Bogen PA Amp

[jjasilli]

Finally found a use for my Bogen CHB-20A PA amp.  I'm using it for a PA amp!  For gigs:  2 acoustic guitars with pickups + 2 vocal mics > Behringer Eurorack mixer > CHB-20A > house speaker.  Sounds awesome; way better than the house Peavey SS powered mixer.

I've procrastinated for years modding this into a guitar amp.  Now I'm glad I didn't.  The mixer & amp together are a lightweight package.  I did put 1/4" input & speaker jacks on the rear. 

I may add a second speaker jack in parallel for a second speaker.  Maybe feed one speaker through an attenuator to serve as a "poor man's" monitor.   

[eleventeen]

You may be the last man alive who actually uses a Bogen tube PA amp for a PA amp.  Good on ya'!

[DummyLoad]

that particular model can be made into a very nice sounding guitar amp.

link to the conversion i made.

of course it sounds good as a mic amp - it's made with tubes, right? 

--pete

[alerich]

Maybe feed one speaker through an attenuator to serve as a "poor man's" monitor.   

Most decent floor monitors have volume controls on them. Mine do.

[jjasilli]

that particular model can be made into a very nice sounding guitar amp. link to the conversion i made.  of course it sounds good as a mic amp - it's made with tubes, right?    --pete 

Yes. You also recommended a 12BZ7 based preamp.  I also have a Bogen CHB-35AS which needs a cap job.  And I'm promised a Bogen MX60A, which seems to have input trannies for lo-z mic's.  So many possibilities!

Maybe feed one speaker through an attenuator to serve as a "poor man's" monitor.   

Most decent floor monitors have volume controls on them. Mine do.

Good point.  I'll check that out.  But these are house speakers at the venue which hang from the ceiling, so hard to access.  One speaker faces the room; the other faces the band area.

[6G6]

Tube PAs are sort of a lost art.
Like guitar amps, they just sound more live and real.
With new SMPS SS amps being so light and cheap per watt,
it's a wonder anyone even uses older SS stuff.

[jjasilli]

The CHB-20A is surprisingly light & easy to carry.  The 35A is noticeably heftier.  Luckily, 20W is more than I need.  The CHB-20A could easily fit into a much smaller chassis.  It seems Bogen cut costs by offering much of the CHB series from 14W - 100W in the same chassis/ metal cab.

[HeyItsBen!]

Thats the CHA20 you posted there. I haven't seen (m)any conversions for the CHB.

-bp

that particular model can be made into a very nice sounding guitar amp.

link to the conversion i made.

of course it sounds good as a mic amp - it's made with tubes, right? 

--pete

[DummyLoad]

Thats the CHA20 you posted there. I haven't seen (m)any conversions for the CHB.

-bp

that particular model can be made into a very nice sounding guitar amp.

link to the conversion i made.

of course it sounds good as a mic amp - it's made with tubes, right? 

--pete

you are correct. sorry for any confusion i may have contributed.

platefire converted one. don't know if he posted it here - well_kind_of_sort_of_did - he just made some minor mods to accept phone jacks and got rid of one of the inputs.


http://www.tdpri.com/forum/shock-brothers-diy-amps/267330-simple-bogen-chb20a-conversion.html


--pete

[jjasilli]

Here's some guitar amp mods for the Bogen CHB-20A. Bog-mod is from PRR.  BZ-GW Stout is from Dummyload.  These are from old threads which may no longer appear on this Forum.  The other 3 I found on the internet.