Hughes & Kettner BassKick 707

[vintagekiki]

Please schematics

tbx

vk

[vintagekiki]

It is still topical

Please

vk

[J M Fahey]

Sorry not to have it, but *many* times H&K has sent schematics if asked nicely and accompanied by serial number.
As usual, try to sound like a repair shop tech, not like a desperate Musician, or "for your own safety" you will be referred to an Authorized Service Shop.

[mozwell]

Hi Kiki
what is the actual problem you have.
If it is the power amp, it may be the same, or very similar to one of the schematics in this thread.
http://music-electronics-forum.com/t25740/
Is there DC on the output ?
Are any internal fuses blown ?
Did you try using a patch lead between effects send & return jacks, or between pre amp out & power amp in jacks ?

Is there power supply on pre amp ic's, 8 pin ic's should have approx 24VDC to 30VDC between pin 4 & 8 (eg TL072), 14 pin ic's shoudl have approx 24VDC to 30VDC between pin 4 & 11.

With power off, measure between pins on power transistors, do any read 0 ohms, any square ceramic resistors shoudl be checked, do they read ok ?

[vintagekiki]

Hi Kiki
what is the actual problem you have

Hi Mozwell

Thanks for the answer.
At Hughes & Kettner BassKick 707 treble control does not work.
Without schematics is difficult to find fault, I would much appreciate it if someone would upload schematics.
Repair is not a problem, I am a telecommunications engineer.
I apologize for English language, only Google translator.

vk

[J M Fahey]

Dear vintagekiki. I don't have the schematic, but a malfunctioning treble control is not that difficult.
Start by distrusting the pot itself, check it or straight replace it, and second suspect: cracked pads/tracks/etc.
Follow the traces to show what they connect to, also state the pot value and curve.
There are not *that many* possible configurations after all.

PS: where are you from/what language do you use?
Good luck.

[vintagekiki]

Dear Juan

Without access to the original schematics repairs professional is quite difficult
Through the good people sent me schematics for Basskick303, but not help because preamplifier Basskick707 have parametric EQ, digital IC HCF4053 ... ...
Measurement of voltage and controlled passive components, I found that the circuit which relates to the regulation of the treble control are correct, there is probably some break in the PCB. With schematics can be monitored oscilloscope signal and find the defect.

You asked me where I was from, and what language I use
I'm from YU and using Serbo Croatian language
For foreign languages that I do not understand I'm helping out with Google translate

Thank you very much for your attention and your understanding

all the best

vk

PS Basskick303 schematics

http://www.tube-town.de/ttforum/index.php/topic,16880.0.html

Jochen Vielen dank und alles Gute

[J M Fahey]

Ok.
I think that following tracks with your eyes , even without schematic, will help you.
Good luck.
PS: I asked because you *might* speak Spanish or Italian, Portuguese or French and I might write straight in some of them, but with Serbo Croatian .... let's Google Translate .

[Jazz P Bass]

Have you verified that the HCF4053 IC functions properly?
There are binary inputs that select which outputs are enabled.
There is also an 'inhibit' pin.
http://bertrik.sikken.nl/bat/pdf/4053.pdf

[Andthegeekshall]

Hi Kiki
what is the actual problem you have.
If it is the power amp, it may be the same, or very similar to one of the schematics in this thread.
http://music-electronics-forum.com/t25740/
Is there DC on the output ?
Are any internal fuses blown ?
Did you try using a patch lead between effects send & return jacks, or between pre amp out & power amp in jacks ?

Is there power supply on pre amp ic's, 8 pin ic's should have approx 24VDC to 30VDC between pin 4 & 8 (eg TL072), 14 pin ic's shoudl have approx 24VDC to 30VDC between pin 4 & 11.

With power off, measure between pins on power transistors, do any read 0 ohms, any square ceramic resistors shoudl be checked, do they read ok ?

Hi I,m new here and i just bought one of these with the knowledge that the pre amp had been bypassed. but when I do the suggested trick with the patch lead in the send return all seems good. what does that imply?

[The Dude]

You could have a bad switching jack in the return position. The previous owner could have cut a trace or unsoldered something intentionally. Hard to say until you open it up and see what gives. You could take it apart and fix it, or you could just keep a small jumper between send and return and use it that way.

P.S. Welcome to the place!

[Andthegeekshall]

Thanks! Gives me a good starting point. I opened it up there's a wire soldered to the VOL pot but hard to tell what they did. i sent an email to H&K asking for the schematic hopefully they'll send one. Thanks again