Hello

This is a nice and rare rack mount tube preamp from the early 90's from Jackson. I have traced the power supply and created a schematic. Its just a simple linear supply.
I was thinking about reverse engineering the whole thing. Leave a comment if you want me to trace the entire thing. If I get enough interest Ill do it.

I posted a YouTube video about it on my channel:

JacksonJX3_PowerSupply.jpg

Peace out.
Pete

Speaker Line Out Isolation Transformer question:

Does anybody know what Type/Spec ‘Isolation Transformer’ Suhr or Bradshaw uses for their Speaker Line Out Boxes? Correct resistances?

Want to attempt to make one.

I see these resistance specs options but don’t know what is needed:
— 600:600
— 10k:10k
— 10k:600 ?

— Xicon, Jenson, Edcor ?

Anybody have any ideas or knowledge on this?

Thanks for any help

So I picked up 7 of these on the Bay for a great price thinking they would be good in tube amp projects. I measured all the resistances for them (see below image) and I'm pretty confident I know what wires are the primary and what are the secondary. The primary is a little strange and worries me because you would think the resistances would be the same on both halves which they aren't. Is there a conventional color coding scheme with the wires? I know black & white for the primary is Line &...

Hi guys.

I am a fan of Blackster FLY3.

It is a 3W amp but its too loud for the apartment I live in.

Specifically, I can only turn the volume knob turn to about 1. Its hard to adjust and its stressful for me :(

If I could turn down the max volume I could turn the volume knob as freely as I do when playing in the studio.

What modifications should I make?

In case you are wondering, I have enough skills to DIY pedals. If its not too hard to mod it, I will do it right away.

Please give me...

I'm trying to build a practice amp using an 8 Ohm speaker and a TDA 2822 IC that will run on 9v pedal power.

For a first attempt, I built the bridged example from the datasheet, shown here:

tda2822-bridged.png

It works, and it's a bit more volume than the usual LM386 amps I've built (ruby, noisy cricket, etc), but zooks its dirty. Like fuzz dirty. If I crank WAY back on the input volume it cleans up OK, but I'm just wondering if I can do anything to make that sample circuit play nicer...

Hello everyone!
Your requests have been heard! I've added three brand new PCBs to my products list 🙂

SLO-style PCB (400mm x 78mm)
Princeton Reverb PCB (322mm x 63.5mm)
Dumblelator PCB (240mm x 35.5mm)

All boards come with full documentation: layout, schematic, BOM! If you want to check out the documentation without any purchase, I've made it available for FREE on my website for anyone to download (just login and you can view/download everything):
If you have any question, please let me...

I want to build or purchase an affordable EL34 power amp, either 2x rack unit or small head format. Absolute maximum 50W, ideal 10-20W, as it is just for playing and eventually recording at home. Only power amp & phase inverter, no preamp, as i have a gazillion preamps either made or in the making for it, and a valve head already.

Any recommendations on DIY kits or ready-made products that have a good quality-price ratio?

Thanks in advance!

davoli-jolly_08.jpeg davoli-jolly_01.jpeg davoli-jolly_04.jpeg davoli-jolly_06.jpeg davoli-jolly_05.jpeg

The date on the schematic isn't really 1955, is it?
Wouldn't that be very early for solid state rectifier?

Davoli DTE 1051T.jpeg Davoli DTE 1051 T.jpeg Davoli 1051T 02.jpeg

The schematic is not complete, what are the stages to the right? And where's the ECL86 pentode stage?
Still the schematic lists the tubes as:
V1 ECC83
V2 ECC83
V3 6AV6
V4 ECL86

Is very much like the little pink amp a restored a few years back. That one was sold off, I just had too many amps around the house, and too little time to play them all. Little Pinkie was very wanted, just because of the color. But it also meant that I had to spend about 275 euro to wrestle it from the hands of some Flemish hipster soccer milf. It needed new tubes, a whole bunch of rewiring, filter caps and a new speaker. Then the guy who bought it haggle down to 350 euro, though I wanted 375....

Hi,

anyone has schematic of this little amp? I own it and am just curious to see what they did.
It's all SMD, so it's a bit of a pain to reverse engineer. Would maybe consider modding the tone stack if it's possible to do without too much SMD work, but it's unlikely.

Tnx,
Bancika

Hi all.
I came across this forum looking for a volume fix for a DOD FX50B and I found it, which was really great after not using that pedal for that particular issue.

So... I began playing the thing through some amps and finally got to my little Fender Frontman 15 which we all know are not quality amps.
That being said, I won't sell it and got to think about modding it up:

1.- Adding a reverb tank. It has the circuit printed, so... could I just solder the missinf components and build a tank...

Not sure if there already is a thread about one of these, but anyway, I thought I would start a thread about my Boss Katana KTN-100 Mk II digital modelling guitar amp, I bought this last year if my memory serves me right, I decided to buy one because a, it's lighter than my Marshall amp so I no longer hurt my back hauling it up and down the stairs near my flat, 2, it has 8 user presettable channels, 3, each of the 8 channels can have up to 5 virtual pedals chained in a row.

The amp also has an...

Since I could not find the documents on the Internet, I post them from my archive packed in ZIP files.
There are schematics, layouts and pictures to find.
Seymour Duncan Convertible Schematics.zip
Seymour Duncan Convertible Layouts.zip
Seymour Duncan Convertible Shots.zip
Seymour Duncan Convertible Instructions.zip

I'm already searching doggedly, but I can't find a circuit diagram for this device. Maybe someone has such a circuit?

Does anyone know where I might be able to find a schematic for the Marshall JMP-1 preamp's footswitch? My friend wanted me to build one for him since they are sort of hard to find/super expensive. He thinks it uses a midi cable. Not sure its something I want to tangle with but was hoping to take a look and make sure...

--Brad

Hi there, I search a bogner fish schematics :)

Thanks

Hello
my Quad Preamp has suffered from being stored during near a decade... yes it's a shame :roll:
So of course I will have to change the electrolytics, all the orange drop capacitors which are on the anodes, and of course... the vactrols ...
Some of them have died at power-on, when I tried to use the preamp after its long sleep in the closet.

Of course, I plan to roll my own 19 vactrols, seeing that the most important specs to target seems to be the R off which should be greater that 50Mohm...

Hi Everyone,

I've just recently been given a Peavey Backstage Plus 35W Solid State guitar amp for nothing, and I'm currently working on it to get it back to a useable state, so, what's wrong with it?

Well, the original speaker is a no-worker but the rest of the amp seems to work fine, I verified this by plugging my pair of headphones into the headphone socket, I get normal sound through my headphones but no sound through the speaker.... :thumbsup

I've managed to find what I think should...