Want to build a small harp amp

[blindboybenton]

Good morning too you all

It was in the 1980-90 i was a harp player in a local blues band using a Peavey classic 50watt and a green bullet. A few years later i stopped playing. Since then ive started playing bass. I would now like to start playing again. Got fed up with carrying shit loads of stuff to gigs.

I want to build a small valve amp. I got a donor chassis and speaker in a combo. Looking though the spares cupboard ive found a Power TX and a few output tx's
New Power tx is out of a 30watt, EL84 amp ....... 295v @130amp and 6.3v @3amp

Looing for a 15-30 watt amp
is there any harp players out there with some advice.

BBB

[MarkusBass]

Have you looked at other threads in this subforum? For example this one: http://music-electronics-forum.com/t17837/ but there are also many others.

Mark

[Leo_Gnardo]

First I gotta confess I'm not a harp player. But I've fixed lots of amps for the local harmonica cats. You have the advantage of building to your own style. I notice a wide variation of amps & tones the harp guys like. Some just use a stock 60's Fender Champ (Southside Johnny) or another manufacturer's version of it, all the way up to Bassman 4x10 or even a Twin (Butterfield used two!). Funky old Gibsons and rarer Guilds, Lafayettes & similar from the 50's & 60's are hauled in by the harpers as well, some with 8" speakers all the way up to 15" Jensens.

Given you have a donor chassis figure out what control set you can fit in it. Just volume & tone to keep it simple or expand to treble, mid, bass if you have the space & panel holes. The 5F6A Bassman stack works well for harp as well as everything else. Also decide whether you want to put in a reverb. I prefer 6V6's over EL84 but no harm if you like the '84 tone and go with them. Half the battle is choice of speaker, so many to choose from, so many tones. Once your amp's built, audition as many speakers as you can get your hands on & get one that pleases your ears. I couldn't predict what will fit you any more than I could recommend a shoe size. One of our newer correspondents here seems happy breaking in his Jensen C8R. If you like mellow tones, hemp cones deliver that and even better with ceramic magnets.

[blindboybenton]

Hi Leo. Its a solid state combo . so i will have too cut the holes. not a problem. there are 3 harp players in the uk near me that i know and both use bassmans. Most seem to use classic 30 or Blue jnr. You say just volume and tone. would a gain control be a good idea?
Im looking at the idea of buying a ready made chassis from TAD in germany, if its going too fit. got to check the sizes
I shall have a look at some schematics for gibsons and guilds

bbb

[Leo_Gnardo]

Hi Leo. Its a solid state combo . so i will have too cut the holes. not a problem. there are 3 harp players in the uk near me that i know and both use bassmans. Most seem to use classic 30 or Blue jnr. You say just volume and tone. would a gain control be a good idea?

Volume & tone was a "keep it simple" suggestion. All depends on how many holes you want to drill & pots to wire up. If it's your goal to push the amp into early distortion, take a note from guitar amps, pre volume & tone control following the first stage preamp, another gain stage into a master volume.

If avoiding distortion is the goal, you could put a volume control between the input jack and first triode, dial down to keep the triode from overloading & maintain a cleaner tone. Some very old amps intended for guitar have this feature. Since the mid 50's you don't see many set up like that. Their designers were probably thinking of those new-fangled 'lectric guitars, some had no volume nor tone controls. The analogy to your harp mic: not many of those have volume controls either. If you choose this route I'd follow the pre with another volume control so you can select the level you need, also cut down on noise developed in the preamp. That's the part those early VC-first designers left out - those amps run wide open & tend to be noisy.

It's mostly a matter of deciding what YOU want in your amp, what your style is, then designing for that. If you drill enough holes and wire up enough controls you could have a lot of tone selections to cover anything you might need. But then it wouldn't be so much a "small harp amp."

"Gain" and "volume" are used pretty much interchangeably, really the same function. "Gain" usually refers to earlier stages but it's still a volume control.

[blindboybenton]

The chassis has a load of holes drilled in for the pots and jack's I will use thoses and then fit some brass plate 1.2mm thick too cover the ones im not using . Im still thinking of if i can fit a pre made chassis
Just waiting for my Green bullet stye copy mic to arrive... No turning back now. When it arrives im going to try it out on some amps in the workshop. Blues Jnr - Super 60 - Peavey classic 30 and mesa F30, See what i like.

BBB