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SUPPORT FORUMS FOR ZKITS >> ZKIT 4 Support forum >> P2P tube regulated zKit4
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Message started by Gilf on 01/20/24 at 19:58:49

Title: P2P tube regulated zKit4
Post by Gilf on 01/20/24 at 19:58:49

The onslaught of cold weather has me stuck inside so I’ve been teaching electronics to my friend’s 6 year old son. We’re about to dive in to our first actual project. Point to point zkit 4 with tube regulated power supply. Got to start them off right.

Title: Re: P2P tube regulated zKit4
Post by Tony on 01/21/24 at 00:37:39

That's a very lucky Kiddo to have you as a mentor.
To both of you, nice work on that base.

Title: Re: P2P tube regulated zKit4
Post by Gilf on 01/22/24 at 18:41:12

Thanks, Tony. I feel lucky myself. It is unusual to have a child with this talent at such a young age. He's going to quickly surpass me and is already keeping me on my toes asking questions that I can't answer.

Title: Re: P2P tube regulated zKit4
Post by Gilf on 02/10/24 at 17:17:17

We are getting close to finishing project and I’m second guessing where the gain control would be added in the circuit.
I was initially thinking it replaced the 100k resistor on the output but thinking logically now realizing this is not correct. I saw in another post that Steve said the 100k pot goes on the output, but where exactly?
It seems like across the input RCA line would be the place?

Title: Re: P2P tube regulated zKit4
Post by funch on 03/24/24 at 22:52:15

I put mine on the input. To me that makes sense. The ZKit4 is essentially a preamp, so the input signal goes to the attenuators (100K), then the circuit, then out.

My build is here. It uses two in a balanced configuration.
https://www.decware.com/cgi-bin/yabb22/YaBB.pl?num=1701983220

Title: Re: P2P tube regulated zKit4
Post by funch on 03/24/24 at 22:54:58

Great looking build btw.

Title: Re: P2P tube regulated zKit4
Post by Gilf on 03/25/24 at 01:12:29

Thanks, funch. I should have updated my post, but didn’t think anyone was watching this section of the forum anymore.
I ended up putting the pot on the input like you said and it worked out well. I misinterpreted Steve’s message about putting the pot on the output of each channel- what I “think” he meant was on the output of the cd player, before the tube stage.

Title: Re: P2P tube regulated zKit4
Post by bobc on 03/25/24 at 14:20:55

I’ve played with the pot on both sides of the zkit. I currently use on output.

On output the full 2v signal goes to the tube and you get maximum effect. Ie good harmonic distortion, and attenuation from there. The signal is “enhanced” regardless of where the pot is set.

On input you control how much of the signal the circuit sees and as such how much”effect” is in resulting signal.

I think it depends on upstream equipment ie if your amp has a pot on input, why add another series pot. Definitely not gain structuring! For my application I am feeding a solid state power amp. I want full “effect” to make this sound more Tube like, so pots on output.

I made one with 3 relay controlled inputs and a bypass switch. I found better ways to tweak my sound, but the zkit is a cool piece and I use it regularly.

Title: Re: P2P tube regulated zKit4
Post by Gilf on 03/26/24 at 00:11:54

Thanks for sharing your experience, bobc. It’s easy enough to swap the wires so it goes on the output the way I laid it out. I’ll try it out. It will be a fun project to do with the kids since they’re begging for more soldering and we don’t need any more gear around. The amp I made with them has no volume control so the tube stage volume is a must.

Title: Re: P2P tube regulated zKit4
Post by funch on 03/26/24 at 20:29:10

I've never looked at it that way. Maybe I'll try it on the output. Mine goes from the ZKit to a balanced-to-SE transformer converter, then to my headphone amp which has a volume attenuator.

Title: Re: P2P tube regulated zKit4
Post by funch on 03/28/24 at 23:31:02

Tried putting the volume pot on the output. Didn't like it. Went back to putting it at the input.

Title: Re: P2P tube regulated zKit4
Post by Gilf on 03/28/24 at 23:41:42

Same here. I use mine with a tube amp so I don’t necessarily need the “full effect”. It’s nice being able to adjust the drive having it on the input. Different courses for different horses. :)