

Thanks for the kind words


Let me know what info you need for the mixer version you mentioned.
Moderator: Joe Malone
Thank you Joe,Joe Malone wrote:WOW Udo looks great. That is one heavy duty headphone box![]()
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Thanks for the kind words![]()
Let me know what info you need for the mixer version you mentioned.
Yes correct. Depending on number of inputs you may need to make the 2 1k gain setting resistors smaller in value to make up any lost gain.kante1603 wrote:
i love this heavy duty stuff,although it´s small it´s heavy-weight tool.
And:"Mine goes to eleven"![]()
I think I´ve got it right now,but still hesitating about how many inputs my little "satellites" will have (maybe 3-4,mixed of mono and stereo).
Anyway: Each should have additional inputs,built of full H-pads with Mono/Mute capabilities.This all connected to the pcbs main inputs to keep the mastervolume-pot (at the IDC or screwterminal,right?).
Any normal solid state output can drive 2k load fine. So with the 20k input per channel that would mean 10 satellite headphone boxes without a problem.Just thinking about the input impedances:How low am I allowed to go?
I´m working on a small active linelevel-distributor,something like 4-6 times 1 input in maybe 4-8 (for putting on up to 4-8 satellites)
The 3 input submix schematic you sent me will work fine. You do not need the 10uF caps on the sub mix H pads.kante1603 wrote:Hello Joe,
me again.
Have decided how to build my "satellites" now:
There will be 4 satellites for now (maybe later up to eight).
Each with 3 inputs in stereo with a mono switch.
Your board will be/have the master level control with mute switch.
So paralleling these satellites should not be a problem I think,but about the loss in gain:
Can you give me an approximate value for the gain setting resistors (or an equation)?
Will send you a schemtaic for one satellite-will you be so kind and look over it?
Thank you in advance,
Udo.
Hello Joe,Joe Malone wrote: The 3 input submix schematic you sent me will work fine. You do not need the 10uF caps on the sub mix H pads.
The sub mix will loss 20dB of signal level. So changing the 1k gain setting resistors to 100R will make up the 20dB and restore the amp head to the usual 15dB overall gain.
kante1603 wrote:Hello Joe,Joe Malone wrote: The 3 input submix schematic you sent me will work fine. You do not need the 10uF caps on the sub mix H pads.
The sub mix will loss 20dB of signal level. So changing the 1k gain setting resistors to 100R will make up the 20dB and restore the amp head to the usual 15dB overall gain.
cool-this will be one of the smallest mixers ever![]()
Thank you very much again,
best regards,
Udo.
Here it is-10cm (width) of pure mixing power!Joe Malone wrote:![]()
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Ok did you test them separately first to make sure each worked properly first? Always the best idea.alistair wrote:Hi Joe,
I've got 2 amp head kits I've mounted together in a box. Previously I had only bothered to make one of them, and it was working perfectly, however I recently finished off the 2nd kit and attached them via a ribbon cable. I've had some problems since then-
OK cap would have to be in backwards to blow. Or a dead short on the opposite rail if you are running zeners and a 36v SMPS rail but this would have blow the same 100uF cap on both AMP HEAD kits.First off one of the 100uf caps (C4) blew, which I replaced both units are now running audio again.
Sounds like a ribbon cable with a short in i or one end reversed maybe. Or opamp in backwards or blown when 100uF cap blew.However, the 2nd unit (the unit connected via ribbon cable) only plays audio out the right side, and the left side is silent.
Like I mentioned before test each AMP HEAD kit seperately with direct wiring to XLR/TRS and power with no ribbon cable. When both work ok then you can hard wire into one and jump power and audio to the next by using a 10pin ribbon with pin 1 stripe going to pin 1 stripe (Do not reverse one end as it will short out everything). If you want to only share power and not audio then strip off the 2 outside pairs of wires so only the center 6 wires in the ribbon cable are left.alistair wrote:Hi Joe-
Just an update- issues with the 1st channel seem to have been related to a faulty input jack. I've replaced this and all seems ok on that channel now, fingers crossed. Explains why replacing other parts wasn't helping!
Still yet to solve the 2nd channel, but I'll keep trying.
Just to eliminate other things, should the ribbon cable remain straight or should it twist? Eg, should the end of the cable marked with the black line go out of pin 1 and into pin 1, or out of pin 1 and into pin 10?
The AMP HEAD would need the 2 PCB zeners to be 24vdc 5w types with the zeners legs left long (zener 10mm or so above pcb) to be able to pull the unregulated plug pack done to 48v. So would make a lot of heat and still may have hum/buzz problems due to the unregulated 48v. So not really recommended but since you have it you could try it if you have 2 x 24v 5w zeners.mike_s wrote:Hi,
I have a 200ma 48v DC unregulated wall wart, that actually measures 61volts. Give or take a bit depending on mains supply variation I guess. Would that be ok as is, or would you recommend regulating it to 48v? Is there any problem with what I am guessing is a diode bridge and a couple of caps in the wall wart, and regulating inside my amp head case? Should I add some more filtering too?
Cheers,
Mike