I think i'm back !

[eschertron]

I can't even understand why anyone would even use them.

And yet many players, pros even, do use the factory presets. I'm thinking there's a parallel between that and the guitar or horn player that picks up their instrument and - obvious to every one in the room except for them - plays without checking intonation.

[daz]

And yet many players, pros even, do use the factory presets. I'm thinking there's a parallel between that and the guitar or horn player that picks up their instrument and - obvious to every one in the room except for them - plays without checking intonation.

If a pro player uses the factory presets on a mustang for cleans, i could see that. But for dirty presets i doubt any pro would use and one of them. The best of them is almost comical. The worse certainly are. The clean tones are not IMO great at all, but the stock clean presets w/o 80 frigging effects aren't too bad and might even be pretty good in some cases especially as a pedal platform.

I'm curious as to how good the kemper and some of the other high end ones are. (i know the kemper is a profiler but it's still modeling amps even if you get to do it yourself) If the mustang can produce such good tones as mine does i gotta think the huge price difference means they must nail that top end i spoke if that i think the mustang has a harder time with than a tube amp.

[dchang0]

daz:

Someday, after enough time has passed for you to decide that this really is the sound you are looking for, perhaps you could take lots of photos of the circuit and post them up here so that others can figure out what the schematic should be... I'm sure somebody would love to draw it up.

Thanks, and welcome back!

[daz]

daz:

Someday, after enough time has passed for you to decide that this really is the sound you are looking for, perhaps you could take lots of photos of the circuit and post them up here so that others can figure out what the schematic should be... I'm sure somebody would love to draw it up.

Thanks, and welcome back!

You'd never be able to, trust me. This amp began life as a 18 watt and have been totally rewired many ways to the point it;s a completely different map with the original board that no longer is valid for this circuit. As a result of there being no room, components are all over the place, solder blobs every where, every type of wire you can imagine much of which is slopped in there ridiculously. Itls truly the sloppiest messiest and pathetic looking thing you can imagine, and many parts are covered up by other parts. It;s utterly ridiculous, and i wouldn't even post a pic out of sheer embarrassment ! I went over a lot of it to make it as reliable as possible because much of it was tacked together in a shaky manner due to my constant experimenting on it. But i can tell you this much. Take a 18 watt with the heyboers they use for those, wire it up with fixed bias and 6V6 in place of the el84's, then design the preamp to be like a jcm800 but make the cold bias stage a regular gain stage like the first stage. Use only the same filters positions in the preamp/PI as with the 18 watt but much bigger. I used a 80uf at the first stages and the Pi has a 47uf. Only because thats what i had and threw anything in to get rid of the small 16uf sprages that were there. Add to one 270pf/470k filter in the preamp instead of the 2 470pf/470k filters in the jcm and put it at the input to the master.

There are other differences but that should get it close, maybe even better. After all, this amp was just a fluke of experimentation. I also put a 270pf treble bleed on the gain pot and made it switchable. So when i'm not using the gain on 10 which is always, (it's usually between 12:00 and 2:00 but who knows where i'll use it when i gig or jam in a band sitch) between the presence, treble, and on.off treble bleed i can really dial in the top end perfectly for any guitar of for my ear's finicky moods that change moment to moment.

However, all that said, if i am still infatuated with this amp after a good while i may draw it up myself just in case it gets lost or stolen or whatever. If i do i'll post it. May even just do it sooner if i get a wild hair or get bored enough.

[dchang0]

The way you describe it makes me even more curious as to what the schematic would be, LOL.

Here's hoping you draw it up someday... I'd build one.

[loudthud]

It's truly the sloppiest messiest and pathetic looking thing you can imagine, and many parts are covered up by other parts. It;s utterly ridiculous, and i wouldn't even post a pic out of sheer embarrassment ! I went over a lot of it to make it as reliable as possible because much of it was tacked together in a shaky manner due to constant experimenting on it.

Daz, Is it as bad as this? I think this is the Rivera era Concert II.




I've seen the schematic online, but never the layout. I found a hardcopy and scanned it. What a mess!

[dchang0]

loudthud, is that a real schematic, or a joke somebody drew up?

I was supposed to fix a Rivera Concert II for a buddy--he never did drop it off, but if it is this bad, I'd have given it right back!

[loudthud]

It's real! On my honor as a bass player!

[dchang0]

It's real! On my honor as a bass player!

That little emoticon--would it happen to be smoking the same stuff that the person who drew up that schematic was smoking?

[The Dude]

[ATTACH=CONFIG]40642[/ATTACH]

They could have at least given that kid some different color crayons.

[loudthud]

That little emoticon--would it happen to be smoking the same stuff that the person who drew up that schematic was smoking?

Not me! Couldn't find an I Swear on a Bible icon.

[daz]

Daz, Is it as bad as this? I think this is the Rivera era Concert II.


[ATTACH=CONFIG]40642[/ATTACH]

I've seen the schematic online, but never the layout. I found a hardcopy and scanned it. What a mess!

Well, one, thats a drawing and i'm sure the lines do not represent the true pathways of the wires, and two, it's not as much the lead dress thats sloppy (tho it certainly is )as the way things are sloppily tacked in, old solder blobs everywhere. Components that have been removed then reused dozens of times with leads that look like you can't imagine. If i had to compare that drawing i would say you can't, but whatever the actuall chassis looks like mine is w/o a doubt far far worse. It's an utter slop fest. You gotta realize it has been thru literally a hundred iterations from a 18 watt to a princeton to a marshall MV and dozens of different circuits between those. It was to me a breadboard of sorts just to experiment and see what sounds like what, not an amp i intended to use as is. But an experiment to learn what the hell i'm doing and to hopefully come up with a great sound, then once done build a new amp thats neat and clean with the same circuit that all that experimentation brought me to. It was the first amp i built and i HATED the 18 watt circuit so i just began experimenting. There are major portions of some stages wired above the tube for lack of room on the board. It's utterly unpleasent to look at. But JFC, it sounds wonderful !!! Go figure.

Anyways, i brought it out of storage recently out of bordom (being out of work and all) only to find i felt it sounds a lot better then the clean builds i made after it. I suppose the smart thing to do would be build a clone thats neat, but 1-i'm out of work with no prospects and the likelihood that i am involuntarily retired on a pittance as of now and 2-even if i could afford to, i know how this goes....you build a clone and it doesn't sound the same. Especially with a amp like this who's tone is no doubt in part due to the insane slop fest that creates it. So in short, i do a jam now and then with friends and occasionally a very rare gig. So really....why bother? It's sloppy as sloppy gets but it sounds fabulous so what does it matter?

By the way, i owned one of those rivera concerts in about 82 when they first came out. I don't recall if i ever looked at the guts but one thing i can tell you.....the distortion channel on those things is GAWD AWFUL! They don't make em like that anymore.....thank god!

[dchang0]

So really....why bother? It's sloppy as sloppy gets but it sounds fabulous so what does it matter?

You kinda answered your question. If it sounds fabulous, it is crying out to be cloned/propagated so that others can share in the fabulousness. It's kinda like how if a dog breeder finds a really awesome dog, he will breed that dog more so as to produce more dogs with those traits.

Post up some audio clips if you don't mind--let others bask in its glory...

[Enzo]

50 years ago, I was in college as a physics major. I took some computer classes. We studied a language called FORTRAN. We had to "type" our programs line by line onto IBM punch cards. We sat at a console with a keyboard, and card after card fed into it from a hopper, and we hit the keys which punched out holes in the cards. The famous hanging chads of the 2000 election.

The punch card machine was programmed by this large panel inside a hatch. It was full of jumper wires that connected various functions. In fact all teh equipment used them, the card readers, the line printers, and the card sorters.

What does this have to do with anything? Well those programming punch boards looked like this:

[J M Fahey]

FWIW I had to repair a Fender Custom Shop amp head, I guess it was a design by "Mr Zinky" or whatever pothead (in a bad way) "guru" they had hired at that point, and it was 3X as bad (not kidding) , it looked like a joke, most parts which were meant to be joined together were placed at far ends of the chassis so you had dozens of wires going end to end many times and others crisscrossing from pots, jacks and switches to tube sockets.
And it was *all* white wire , no colour coding at all, except for transformwr wires which were factory coloured.
Not kidding , the amp must have weighed an extra pound just because of all that wire.