Hi
This is certainly not stompboks, but I'm sure that they will help me here)
Since there are no schemes in good quality on the Internet, I attached the lonestar scheme, as the closest analogue.
I'm interested in one question, before the last stage of amplification is the RC filter 2M2 // 20p, I'm confused that the resistance of the resistor is very large, and the capacitance of the capacitor is very small.
As far as I understand, there will be a large loss of volume and also this filter will...

So, I wanted to add some EQ options for my home stereo system, as it currently has no EQ controls. I'm gonna mess with the LM1036 chip. I was lazy and just ordered a mostly prebuilt PCB of the stock data sheet circuit. Its got controls for Volume, Bass, Treble, Loudness, and Balance. All fine, except I already have a balance control in my system and don't want to add another one. So, any ideas as to how to remove the balance control so its just fixed at 50/50. The PCB should arrive in a few...

I have a Laney Cub 10 which has a nice crunch to it, but even with a speaker upgrade it's a bit dark. If my tone control would only go to 11..... Anyway single coils and bright humbuckers are great but I wouldn't mind a bit more brightness for some other guitars. A schematic of the amp is here:

On TGP a simple mod was posted for achieving this goal but before I tear out the iron and break something I'd really appreciate if someone that knows what they are doing wouldn't mind taking a look....

Could anyone give me very general idea of how elements like air conditioning controllers so the parts where in a car you setting up temperature, with led displays etc are programmed nowadays? So assuming we have a plastic panel with buttons on it, led display and what not, and when I press + I want temperature to be increased or some mechanical parts to take action.

I'm guessing that there is ROM and some CPU chips: where software controlling the parts is stored. Now this software is usually...

Hi folks,
I have a repair for a friend who has a Crate CA125 acoustic amp. For once, I can't find any schematic for an amp online.

Any help appreciated!

Thanks

Wanna know if anyone might be able to get or find a schematic for a Kustom X MPA MONOURAL 135 @ 8 ohms Power Amp
which was made in the early 70’s....
When I hook up this amp through a p.a. System I get sound for about 5 minutes and then it starts to have an unbearable LOUD hiss which cannot be controlled by the volume at all...
I then turn it off....
Any help would be appreciated.....
Jim

Say that I would want to use a combo as a speaker cabinet, do I simply ad a jack that goes to the speakers, impedance aside, are there any other issues?

I was needing a new amp which is smaller than my usual setup so my credit card treated me to an EVH 5150 combo until I am able to sell my older amps to pay Mr. Card back.

My first impressions are good and the sound is great, ch3 is so dirty it's unbelievable whilst ch2 has the definitive Van Halen sound but can be dialled up with different crunch sounds. Ch1 which shares all the ch2 controls goes from clean to dirty very quickly with the gain control.

Now here is my first problem, as ch1 and...

This is my first and (until recently) only guitar amp. Served me well gigging every weekend in a decently popular working band, but its too big and loud for what I do now- bedroom playing and home recording.

It also started acting up a while back- scratchy pots, and intermittent feedback on the distortion channel. Local music shop sends them away to an electronics repair shop, which charges $80 to diagnose the problem, then $80 and hour (minimum 1 hour charge) plus parts to fix it.

I was...

I was using my Danelectro Honey Tone amp with an audio signal probe I built to troubleshoot audio circuits. It worked great until I used it to probe a tube preamp circuit. Now there is no output. I think I blew the op amp (TL072) because the signal is too high in a tube preamp. I will replace the op amp as soon as I can get one.

What would be the best way to limit the input signal to this little amp? Would zeners on the input be a good way to limit the input signal?

Mike

Yeah yeah I know there are tons of examples of music driven LED circuits out there, but they mainly control just one LED or one string of them.

I want to make a circuit that will control quite a few LEDs, with each LED at a different range of frequencies.

And I will use Linear-Amplifiers LT1366 (see ) this Instrumentation, a class of OP Amplifiers to link my circuit. :horsey:

To do this, I am planning on making an array of band pass filters. Each filter would drive a different LED (or...

good day

i traced my amp tonestack and i found this check below pic..when i turned down the all knobs to zero the output signal of my amp lost i mean no output at the speaker..is there a problem in the components of this tone stack?? when i turn up the knobs again the signal came back..??sorry my amp lots of problem its a cheap amp i think from elswhere i dont know..

any advice or opinion or solution??

thanks

I am working on this nice little 60s Italian PA tube amp... It sound very good in stock condition thanks to some smart tricks: shielding the preamp and feeding it negative voltage for the heaters. But the PI is something I have never seen in a guitar tube amp. Both plates of the sides of the PI are connected to the output tubes, but there is an extra connection between the cathode of one of the PI sides to the other output tube.

Can somebody explain why this is done or how it's called? thanks

I'm almost sure the double inputs were not designed to do this, but it's a great mod. In fact, it's just coupling the inputs, but with some resistors? Is there then 130k between the two channels in a Deluxe?

Screenshot from 2018-03-28 21-43-27.png

I'm just trying to squeeze some distortion from this this dual input PA tube amp with 2xEL34:

Screenshot from 2018-03-28 21-52-34.png

I would like to wire this up with a switch, maybe even make V1b a dedicated distortion path. I think I tried...

Hi. I'm using an old Carlsbro Glx 80 for about 20 years now.
It's well maintained but suddenly the preamp section on both channels went really weak (I checked the other sections - power amp in, effect send- and they work fine) .
I can't figure out what could have gone wrong since all the mechanical parts work ok....Leads, pots, etc. .
I 'm not sure how it is constructed so I'm looking for any relevant or specific documentation (service maual, schematics etc.) of any model of the Carlsbro GLX...

I've seen various threads here and elsewhere about the F-2B bass preamp.

There's plenty of talk about a 2-tube version with the 2nd tube providing cathode followers. And some talk about just using an irf820 source follower to buffer the output for better compatibility with power amps that have lower-Z input.

Didn't see a schematic. I'm not super well versed in how this stuff works, but did find some sites discussing how to implement, in general terms, a mosfet source follower to a tube...

Hi there,

My lovely wife is so lovely that she played the guitar long before knowing me, even though she doesn't play anymore... She has an Epiphone Les Paul and an amp, which was stored in her parent's attic. I went seeking for it yesterday, and it appears to be a Ross RGR 25.

Nicely built (see the pic, it looks like a Cornish pedal!! :lol: :lol: ), nice sound too for practicing, but some pots are more than scratchy, even with good cleaning, and the EQ might need some alterations... I can...

I Haven't had much action around these parts lately, and the channel switching in this bad boy started acting up, so let's get the trace show running.
I haven't seen schematics for these elsewhere :horsey:

First up: Board A - the preamp board.

IMG_7828.jpg
IMG_7837.jpg
combo1.jpg
combo2.jpg
combo3.jpg

Board B contains the power amp and tube driven effects loop. I'll take photos of it as soon as I finish tracing board A.

I have a Korean made Synsonics 12 volt DC solid state guitar practice amp.
I know nothing of the ownership or usage history. I got it cheap with some cables, strings, and a stompbox.
Anyway, when I plug it in and turn it on it hums.
However, the power-on LED does not come on.
Also, when I plug my guitar into it, and play, no sound comes out.

I am in need of diagnostic/repair advice.
Any help is greatly appreciated.

If this post is in the wrong place, I apologize.
I haven't been a member...

Hey guys, finally starting my BE clone... Using some pretty heavy transformers from InMadOut. For now I'm keeping it bare stainless steel, I like it quite a lot. Built according to the BE100 2016 specs, and using my custom made PCB boards

Hi everyone,
a friend of mine gave me a Marshall Bass State B65 combo. The transformer is broken, it's a Dagnall transformer type D9609.
The final stage of this amp is very similar to Valvestate V65 amp, whit T64-T65 power transistors:

one of the mainly differences is the couple of resistors R101-R102, they are 470 ohm in B65.
The trafo specifications for Valvestate 65 are Dagnall D9601 or Drake 784-352

I need some help on get the transformer specifications, I think it could be a 24-0-24...