What makes an amp the best Harp Amp?

[MWJB]

Kinder seems not to be building at the moment, there was talk of him firing back up...

There is also the OP on this thread (Bruce Collins/Mission), DJL/Megatone, Kendrick, Clark, Victoria, Marble, Scooter Berberian/Meteor, Mergilli.

Some of those mentioned are building Fender designs that work well for harp right off the bat, some are building amps designed from the ground up for harp...or both, or tube PA inspired amps (Skip Simmons does a good trade in refurbed & modded PA amps) or Fender based amps with a couple of harp-centric tweaks. Some of the amps mentioned work great for guitar, either as they come, or with a couple of tube subs.

Basically, "specifically for harp" covers quite a spectrum & there is no real single or specific way to achieve this...whatever instrument you plug into the amp is kind of moot...the thing still has to function, so whilst you may employ certain techniques, or encourage certain existing characteristics, an amp made "specifically for harp" may still share 90%+ of the circuit/topology with an existing MI/PA amp.

I do quite a bit of "specifically for harp" work, which has included major mods, subtle mods & on some occassions, blueprinting a stock Fender.

[paggerman]

My next door neighbour is a harp player - one of only a handful of decent 'for hire' players in Australia. He Uses a Bassman as his regular gigging amp. He also has a GA30 Invader and a little Supro Champ style. However, I bought a piece of junk a few weeks ago and I grid it and really liked it with my guitar (I really need to learn to Play properly), so I invited the harP player over. He says it's the best sounding amp he's ever played. The line up is EF86, 12ax7, 6v6*2 and iirc 5v4.

It wasn't even designed as an instrument amp.

[MWJB]

"It wasn't even designed as an instrument amp."

Ha ha...many amps that are well regarded for harp were designed as low cost sound reinforcement/"hi fi", like Masco, Bogen, Geloso etc.

Always bear in mind, the amp doesn't know or care what the signal source is...it just does what it does, with what it is given.

[Bruce / Mission Amps]

Yeah, I think a big factor in all this... is that the blues harmonica (as an instrument) is well centered in our vocal range, so many old school vacuum tube PAs seem to work pretty good right out of the box, especially if the speakers are right.
Now, I'm not really talking about modern sound reinforcement PAs... those do everything.

[RitzRed]

did you ever build the harp amps? if you did do you want to sell one what tube configuration did you use

[Bruce / Mission Amps]

did you ever build the harp amps? if you did do you want to sell one what tube configuration did you use

Oh yes! I ran the first run of 24, 1x12 Chicago 32-20 harp amps out in a fairly short time.
I'm very quickly closing in on a total of 100 dedicated harp amps from this original Chicago 32-20 idea.
And, I am currently up to number 69 on the newest chassis seen on my website:

Mission Harp Amps - Blues Harmonica Amplifiers - Home

Although they all sound terrific, the 1x12" is not quite as popular as the 2x10" amps or the 12"+10" amps and 3x10" amps.
I have done a couple each of the 1x15"s and 12"+8" amps too.
My next variation is a 55-60 watt version with 4x10"s....have the cabinet but have not had time to put a demo amp up yet.

The tube configuration I like the best is
5AR4/GZ34 rectifier, 2x5881s power tubes, preamp tubes are 12AX7 and a 12AY7.

Here is a clip of the 32-20 3x10 with 17 year old, Nic Clark and my buddy Al Chesis from the Delta Sonics playing with Bad Brad om guitar another youngster here in Denver.

http://www.youtube.com/watch?v=6CHsu...feature=relmfu

[RitzRed]

I am looking for a harp amp with a 8 inch speaker with balls maybe 12AX7 6L6 5UY something that will distort a bit without feeding back but I am not sure on the tubes do you make anything like that maybe 7 Watts or so if you do make it how much do you want for one?

[RitzRed]

I have an old tube amp with the 5Y3,tube it has 1, 12AX7 and 2 6V6 tubes this amp was pulled from a working 1957 Magnivox consol do you think this will make a good harp practice amp? and what kind of speaker would you use? I have different speakers I can use I have 2 vintage Zenith 12 inch full range alnico speakers 8ohm I also have 4 Celestion 7080 12 inch 16 ohm speakers but I want to use what ever speaker will sound the best for harp so if you think a 8 inch speaker would be better I can find one

[arnenym]

I have an old tube amp with the 5Y3,tube it has 1, 12AX7 and 2 6V6 tubes this amp was pulled from a working 1957 Magnivox consol do you think this will make a good harp practice amp? and what kind of speaker would you use? I have different speakers I can use I have 2 vintage Zenith 12 inch full range alnico speakers 8ohm I also have 4 Celestion 7080 12 inch 16 ohm speakers but I want to use what ever speaker will sound the best for harp so if you think a 8 inch speaker would be better I can find one

You can't tell if it's ā good Harp amp just by looking on the tubetype. This configuration give some hope, but,,, it is a lot of other things in a amp decide how the sound gonna be.

[RitzRed]

what are the tubes with the 6AB4,what is there function and what tubes are they comparible to?

[Jazz P Bass]

Type in: 6AB4
http://www.mif.pg.gda.pl/homepages/frank/vs.html

[RitzRed]

yes I already went there but it did,nt tell me much and I don,t understand what (function t)means it also does not give many different tubes comparible

[arnenym]

yes I already went there but it did,nt tell me much and I don,t understand what (function t)means it also does not give many different tubes comparible

It don't give many different comparible tubes, because there ain't many.
It is a single triode preamp tube with 60% amplification factor...

[Bruce / Mission Amps]

You can't tell if it's ā good Harp amp just by looking on the tubetype. This configuration give some hope, but,,, it is a lot of other things in a amp decide how the sound gonna be.

Right... although I've never heard a really great sounding harp amp using one or even two 8" speakers.... at least it sounds like you have some decent transformers to come up with about a +12 to 16 watt harp amp.
As far as a very loud practice amp... sounds like you have almost everything except a circuit... I suggest you look at a Masco 18 and copy that for a pretty good start.

[RitzRed]

ok thanks can this tube be replaced with a better tube that would make the amp louder without changing allot of other parts on the amp?