i need a mono tube power amp

[Guest]

i am looking into getting a mono amp to use with my pod pro. there are a few new things on the market just for this purpose--atomic makes one. no knobs at all, just an input from your guitar pre. marshall also makes a "el34" amp, but very expensive.

once apon a time i took my dads bogen pa and mounted it in a homemade box with a 12" speaker. the thing actually was very cool. for distortion i just plugged in a pedal. i found a challenger(bogen?) at a pawn shop yesterday while lookimng for an amp. it has base and treble knobs, mic in(very old school style plug) and phono in. i dont see anything similar to a line level input. the guy wants around a 100 bucks for it. i thought i'd wait and ask around to see if anyone knows about a simple cheap kit that i could throw together before i start trying to access a post-phono/mic insert point on the challenger. i am doubtful i could find a schematic for it, and i know very little about tubes. low wattage is ok, it's just for recording. 20 or 30 watts would be adequate. thanks for any ideas.

 

[CJ]

Don't laugh, but a friend of mine who is a pod finatic plugs his into a home stereo and it sounds killer, at least over the phone.
He also uses a bboombox with good results.
You just have to find the right boom box.

If you want to build your own amp, Kent has a cool 18 watt EL84 project.
I do not know if it is still at his site.

The Bogen's had in-expensive output transformers, so....

cj

 

[Guest]

i am using a home stereo boom box. people cant believe it when they hear it. it gets pretty loud. i just want to try some tube stuff. thanks for kent idea, i will read about it.

i am trying to remember this stereo tube unit that i had a many years ago that i was using for headphones. it was nice till a choke or coil in it melted. it was a brown box with mesh. pretty sure it was a kit, using rca inputs...possibly a dyna stereo 70

 

[asm]

check out my thread in the Brewery, titled "old bogen, rca tube amps..."
i got one for guitar. should be here shortly for me to play around with. just look on ebay under the mono power amp section. TONS of stuff going for under 30$. insane.


t

 

[PRR]

> mic in(very old school style plug)

Feed your gitar to those inputs. Same thing.

If you can't find the adaptor any more, knock the Amphenol connector out and out in a 1/4" jack with two washers.

This better be tubes, better work fine, and $100 is still too much.

 

[Guest]

thanks for the ideas.

yeah i already had read the thread on your bogen purchase. let us know how it works out. i am using a pod with line outs, so i was thinking i'd have to really turn the pod outputs down to use the mic in's, plus the mic in's are probably a lot noisier than if i could tap in somewhere after the pre circuit. the pod outs are pretty hot signal.

 

[MikoKensington]

I would think that if you're using a POD you would want something with a fair amount of headroom. If the POD has a hot output it may overload the input of an old tube power amp or PA. What about an old tube "hi-fi" amp? Something along the lines of a Heatkit W5M.

I've used old tube MASCO PA's with guitar. I had to remove the old threaded Amphenol connectors. Great tone, but I think a POD's presets would get lost in translation.

 

[Sleeper]

You might look at something like a dynakit as well. I have a pair of MKIIs... one for my sub and one that I use for driving bass and guitar cabinets when I need to record through a cab and not direct. Maybe I'll get a twin and and an SVT someday, but everyone seems to like the sound around here. They were real easy to fix up too.
Sleeper

 

[Guest]

i used to have a stereo 70. i tossed in in the garbage after a choke in it almost burnt my place down. funny how your appreciation for things change.

 

[dukasound]

Hi
Small amps can be killer :grin:
Two –three years ago I build one preamp with 5W single-ended amplifier with speaker simulator.
I used for power amp both mains and output transformers from old radio. This unit use two 12AX7 (ECC83) tubes for preamp and EL86 for power amp. Speaker simulator is Marshall schematic with ICs and 9VDC suplly. Preamp is based on D*mble preamp. First I mean this unit can use for practise but after tests I mean this is serious gig. Also I put stereo jack for FX loop, switches for on-of 5W amplifier, speaker simulator and volume pot for speaker simulator. This is two switchable channel preamp (clean overdrive) and have jack for switching with pedal (and mini toggle switch on back). I put one mini cooler (PC processor) for cooling EL84 in chassis. When I switch on power amp cooler is on too.

 

[Scodiddly]

Heh - "dukasound" reminds me of an old DuKane mixer/amp I modded a few years back - stripped it down to the power wiring and turned it into a cross between a Fender Bassman and a Marshall 50-watt (the two are surprisingly close). It became the "Uncle Duke" amp. Still in use by a friend in Wisconsin, although he keeps saying he's going to send it back to be recapped.

 

[Gus]

I know someone that has converted PAs, mono amps etc to guitar amps for years. The trick seems to be letting the amp tell you what it wants to sound like, a fender, marshall etc.

Not meaning to sound new age at all it seems to have to do with the power and output transformer as well as the B+ voltage.

The output transformer part is easy to understand the lams and winding style.

The power transformer and B+ are connected. I think it has to do with the winding R and current/power output (VA). With guitar amps you sometimes want the sag of the power supply. The B+ relates to the plate voltage on the load lines.