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Hello from the new guy

Started by edvard, March 17, 2018, 10:30:24 PM

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edvard

Howdy folks, I'm here because I want to learn about building and modifying solid-state amps.  I have used many SS amps, but was never satisfied with any of them (probably because I never had the money for a decent one).  These days I still don't have the money, but I do have buckets of parts and a soldering iron (and I know how to use it!!).

I've built pedals for myself and friends, and lately I've built my first guitar.  I've been reading a LOT and I think I'm now ready to explore the world of high(er) power guitar foolery.  I have a LOT of questions (for other threads), so let the hijinks ensue...

I've read Teemuk's book (or at least, most parts of it; great resource, my hat is doffed), perused Elliot Sound Products, and bought a handful of chip amp modules just to make noise with until I can get something better built.
Anyways, onwards and upwards...

Enzo

Hi


And may I add, the single one thing that can change an amp's tone the most is the speaker.   SO never assume the whole deal is changing a IC or transistor.

edvard

Undoubtedly, which means yet another expense, and I really don't know about speakers, so I'll have to be careful.  Seems like the cheapest "good" speakers are upwards of 60 bucks, so I gotta spend wisely.  Too bad most speaker descriptions are as full of marketing-speak as the rest of it.  I'll save speaker questions for another thread.

Thanks, see ya around...

Enzo

Don't buy speakers and hope.  Go out and listen to speakers.  Play through as many amps as you can have access to, and note what speaker is in it.  Learn from that.

A good speaker is one you like.  All the hype and reputation is irrelevant.  If you like some "crappy" speaker, so be it, you like it.

edvard

All I want is 50-75 watts, with no "British Voicing", tight but not absent bottom end, with not overly harsh high end.  Oh, and less than a hunnerd bucks as well (emphasis on "less").  I know, compromises abound, but "good enough" is what I've lived with most of my life.  Either way, I have a couple amps here that I can hijack their speakers for experimenting, so I'm not immediately lacking. When I have the budget for some "real" speakers, we'll talk...

Enzo

Be creative.  You might find mates with blown amps you could get for free or cheap.   Take the speaker out and use it.   Or you might find a relatively inexpensive working amp with an interesting speaker.  Swap one of your speakers for the one in it, then sell the amp.

J M Fahey

Lots of people improve their amps by swapping the "factory" one for one of the "famous/expensive" ones, say they pull the "black painted" "house label" speaker from, say, a Peavey or Fender or Crate amp (all USA made of course) and put an expensive (and doubtlessly good sounding) Celestion V30 or G12H or Creamback there.
They have no use for the old black nameless speaker so they junk it, or offer it on Craigslist for $20 (and even so they don´t sell) or a garage sale for $5/$10 tops.
Guess what? if the amp was USA made (any one through the 90´s and Peavey up to 2000 or so) then it´s 90/95% possible that speaker was made by Eminence, and wholly comparable to any Legend series.
In fact I think Legends are basically a selection of their most popular OEM offerings, think the generic speaker inside a Fender or Peavey, just labelled and put inside a printed box (instead of an OEM brown or white generic box) so it can be sold to the general public.
They will work very well in your amp, and for a very low cost.

edvard

Hadn't thought of that, thanks.  I've also found a guy on eBay who sells old speakers pulled from organ units and the like.  Many of them look like re-branded Jensens and others, and many are dirt cheap.  I haven't seen any 'victim of an upgrade' speakers on my local Craigslist, but I'll keep looking...

phatt

Quote from: edvard on March 18, 2018, 05:33:31 PM
All I want is 50-75 watts, with no "British Voicing", tight but not absent bottom end, with not overly harsh high end.  Oh, and less than a hunnerd bucks as well (emphasis on "less").  I know, compromises abound, but "good enough" is what I've lived with most of my life.  Either way, I have a couple amps here that I can hijack their speakers for experimenting, so I'm not immediately lacking. When I have the budget for some "real" speakers, we'll talk...

Well tel us what those other Amps are that you have laying around because you may find you already have got most of what you need. :tu:
They may only need small mods to better suit your needs.
And maybe add a link to schematics of same if you can.

Also if you want an easy 50 Watt power amplifier then look at the LM3886 power chip, there are many circuits and PCB's on the net for that chip.
Phil. 

edvard

#9
Quote from: phatt on June 05, 2018, 06:31:09 AM
Well tel us what those other Amps are that you have laying around because you may find you already have got most of what you need. :tu:
They may only need small mods to better suit your needs.
And maybe add a link to schematics of same if you can.

Amps I own at the moment:
-My grandfather's 1952 Fender Deluxe 5A3, which is a great tube amp, but it doesn't do the Rock thing so well, and I'm a metalhead from way back.  It's amazing how much this thing doesn't distort.
-Park Bass GB 25-12. It's a bass amp, no more, no less, and doesn't distort either.  Currently doing duty as the speaker for my science experiments.  More about that later...
-First Act MA214.  Small practice bass amp that came with the bass my wife got me for Father's day a few years back.  It sounds OK with guitar, as long as you've got a good dirt box in front of it, and even then it's just OK.

For my current plans, I've got the cabs and head of a Crate G200C XL "Mini-stack" that I bought new in '89 and gutted YEARS ago after the power section blew, and I couldn't find the chips for it.  This was back before the internet could have gotten me 2 TDA2030s to fix it for less than bus fare downtown.  The cabs are loaded with four 6"s each and they sound awful; imagine shaking a sackful of marbles and that's what distortion sounds like through these cabs.  My current goal with that is to replace the arrays of 6s with one 12" each for true girth.  I need to find ones that will do OK in smaller-than-average sealed cabs though.

QuoteAlso if you want an easy 50 Watt power amplifier then look at the LM3886 power chip, there are many circuits and PCB's on the net for that chip.
Phil. 

Yep, I've looked at that one many times but could never afford it, and I had the hots for some TDA2050s before they went out of production.  At the moment, I've managed to snap up a couple LM1875s and a TDA7294 with some Christmas money, so I'm not out of options.

I'm thinking I've finally got my thoughts straight on what I'm going to do with all this silicon and hubris; I'll post in the relevant section later. 

phatt

OK as for the TDA7294 you will need a beefy power transformer to get the max wattage from that. It's possible the Crate preamp could be tweaked and used as the preamp section.
Phil.

edvard

The Crate board was cannibalized for pedal parts years ago.  I was never 100% happy with the preamp anyway; I had to crank up both volume and gain to get a decent sound out of it.  At one point, I had audacious plans to house a tube amp in the head, but those plans never panned out (power transformers are spendy!), and I'm not in the mood to deal with tubes these days anyway.  The amp was rated for 20 watts output (2 TDA2030s at ±12 volts to make ~10 watts each), so the original transformer will have to go to something else.