Hughes and Kettner Trilogy switching

[Alex R]

Just wondered if anyone had seen an issue like this and solved it. It has programmable switching - three channels, two boosts, MIDI, FX serial/parallel, and no doubt other unnecessary but marketable hostages to electronic fortune that I have forgotten about. A programmable control chip receives momentary voltages from the buttons and lights the LEDs and controls a latching switch IC that controls the 22v relays. Most of the buttons don't function right in all kinds of ways. You can't get clean from crunch, you have to press FX serial to get lead, etc etc.

I checked the 22v relay power supply and the 5v power supply that runs all the switching, and I checked the grounds, and the mechanical switches, and all are good. I can switch things properly from the latch, and the 5v momentary sends to the control chip from the switches seem to arrive at the chip terminals ok. A new latching IC made no difference. A new control chip turned all the switching and all the LEDs off such that they couldn't be got back on again. The old one restored the fault condition as before.

H&K were very helpful about new boards, which is going to be the answer I guess - not too horribly expensive - but 8-10 weeks lead time, alas.

Well the amp needed other work too and the guy is off on tour and needs it pronto so I settled it down on the clean channel and said, use effects pedals. When he returns I'll put new boards in I suppose. But like I said I just wondered if anything occurred to anyone.

The CPU thing is one of these: ATMEGA8L-8PU

The latching switch IC is a 74HC595

[Steve Conner]

You said you tried replacing the "control chip"... did you mean the ATMega thing? The firmware is inside that chip too, and if you just buy one from Farnell it obviously won't work because they're supplied blank. You'd have to get a programmed one from H&K.

[Alex R]

I had no idea! Thank you Steve. That could save a lot of money and trouble.

[Alex R]

Happy ending thanks to you Steve. Hughes and Kettner's UK distributor sent me a programmed chip for nothing, I plugged it in just now, and everything worked! Once again Steve, heartfelt thanks.

PS how do you go about programming one of those things?

[Jazz P Bass]

Microcontoller programming

To program a microcontroller you need the code & a chip burner.( a device that writes the code to the chip)
In the past I've used Needhams EMP-20 for burning PIC ic's.

[Duck!]

Happy ending thanks to you Steve. Hughes and Kettner's UK distributor sent me a programmed chip for nothing, I plugged it in just now, and everything worked! Once again Steve, heartfelt thanks.

PS how do you go about programming one of those things?

I hope you can excuse my bad English I am from Argentina .... going to win but I have the same problem with atmega me know if possible I will spend this firmware so I can burn it here in Argentina

from already thank you very much!

[Jazz P Bass]

The firmware is propietary to H&K.

I have run into issues with these where the supply voltage for the ic had a bad capacitor.

Try that.

The IC itself can be purchased from H&K.

[Duck!]

be possible that you indicate me how to do to buy one

[Duck!]

The firmware is propietary to H&K.

I have run into issues with these where the supply voltage for the ic had a bad capacitor.

Try that.

The IC itself can be purchased from H&K.

please help really do not know how I have to ask who the replacement or address

[The Dude]

Not sure if this will help you or not unless you speak German, but here's a link to their contact page:

Impressum - Hughes & Kettner

Also, Yorkville Sound Inc. is listed as their US distributor. Here's their info:

Yorkville Sound, Inc
4625 Witmer Industrial Estates
14305 Niagara Falls
Tel.: +1 7162972920
hk.usa@yorkville.com
Yorkville

I'm not sure about Argentina, but maybe one of these places can point you in the right direction.
GOOD LUCK TO YOU!

[Jazz P Bass]

Kontakt - Hughes & Kettner

[Duck!]

Thanks for your great help!

I hope to solve this problem

[Duck!]

please help really do not know how I have to ask who the replacement or address

hello!
still do not receive any kind of response from Hughes and Kettner ... if anyone has another option that can help would greatly appreciate it

[Jazz P Bass]

You maybe could try to get in touch with Any of the International distributors.
Send them all an email.

[igaar]

Hi,I don't come on here very often but I've got an HK Trilogy 100 watt amp on my bench, i can't find a schematic anywhere for this amp, I'm hoping someone or you perhaps can send that one to my email at igaar@live.com or tell me where i could find it, I've spent hours looking and found many schemos for other HK amps but not this one. HK isn't answering email and only provides op manuals for support. I figured out the the hum issues, more power caps in the preamp supply fixes that, but this amp has a ridiculous amount of gain, the preamp stages are not very well designed to handle that and 2 channel masters and a 3rd global Master? it's like a PA mixer then a guitar amp, the supply decoupling circuit is minimal and could use some more decoupler caps and different power resistors in it.