The Amp Garage

Hi Alexander, great job, I have some questions for you if you like. The foot switch is a stereo jack, what do you control? reverb, Boost, Dirty? Is the dumblator really useful in this type of amplifier that already has the reverb on board? and please ... clips, clips, clips. I have more questions f...

Hi Alexander (alkuz1961) great job. Just out of curiosity, I noticed a pot on the top left of the amp labeled "boost". How does it work? I also noticed a number of interesting differences from the JM / WONDERLAND / CERIATONE JM classic schemes such as the potentiometers and the switches on the effe...

I'd love to hear sound clips where someone demos all of the different Dumble era sounds (or at least low plate classic, low plate skyliner, high plate skyliner, hrm skyliner, and bludotone) so I can actually hear what they all sound like back to back. I've only ever seen textual descriptions of eac...

Once upon a time I was engaged in the repair of tube TVs... should note, 25 kV from the kinescope give a good boost of energy)))
After such a shake-up, you become very careful... for a while ))

ijedouglas wrote: ↑Tue Jun 29, 2021 1:36 pm BTW KWS uses rebuilt fenders with pedals

I read somewhere that all of KWS fenders were modified by HAD

It seems to me that the number of fuses is a little excessive))) I would exclude them, and install a rectifier board in their place. And I would install a transformer on the vacant place, just as it is done in the original amplifiers.

The major cause and problem at this point is that the relays get about 1.6V. They need 5. I get a reading of about 2.5V at the output of the small rectifier that is fed by the filament wiring, 6.4VAC in this case. That is even after disconnecting the relays from their power supply. Probably the hea...

https://ampgarage.com/forum/viewtopic.php?f=5&t=31084 here are all the answers

If the tubes in this amp are 6L6G, that's not important, but if it's EL34 then it could be a problem.

The real amps do this too. It's a bad design tbh. Freidman changed later models to have a 2.2M in place of the 10M pull down resistor. There is also 10uF cap in series with a 100R resistor across the relay coil, which helps slow down the relay a little. I don't think you'll ever get rid of the pop ...

Dunno, don’t think so but not sure, a picture (in this case a schematic) would speak a 1000 words. Surely it would be quicker to try it than debate its potential merits or otherwise? Yes, of course, I will check all possible options for correcting this problem. Thank you for the additional ideas! B...

I wrote that I tried to install a capacitor (10uF) parallel to the relay coil. And it doesn't help with the problem. Isn't that the same thing?

pdf64 wrote: ↑Mon Jun 07, 2021 4:30 pm How about the switch, eg cap across it?

This is a togle switch with three positions. It controls two relays. The first position control the clean/crunch relay. And this relay behaves absolutely quietly. The second relay switches the BE/HBE modes and it is this relay that pops.

What’s the circuit around the relay coil, ie how is it being suppressed? I use rectified heating, and relays are connected from this power supply. A diode is connected to the coil as standard. I tried adding a 10uF capacitor, parallel to the coil, but it didn't improve anything. I have already writ...

Thank you xtian, this is a good solution, and I hope this should fix the problem. But I'm still interested in the cause of this effect. There is no potential on the contacts, but it clicks. And besides, a similar solution is used in the prototype and this problem does not arise there.