Feeler: Classic Solo

GroupDIY Audio Forum

Help Support GroupDIY Audio Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
Hi,

On the new 4Toggle pcb, it looks like the resistor designations have changed a bit from ClassicSoloLoHumBuildInstructionsV0.2. Just to be sure I have it right, it looks like:

R1,2: 6K8
R3: 150
R 4,5: 680
R6: 3K3
R7: 150
R8: 3K3

Is that about right?
Best,
Clint
 
Hi,

On the new 4Toggle pcb, it looks like the resistor designations have changed a bit from ClassicSoloLoHumBuildInstructionsV0.2. Just to be sure I have it right, it looks like:

R1,2: 6K8
R3: 150
R 4,5: 680
R6: 3K3
R7: 150
R8: 3K3

Is that about right?
Best,
Clint
I just checked the PCB layout and I can confirm those are the correct values.

Cheers

ian
 
Last edited:
I am glad you like it. My friend Pierre hosts an independent gallery of people's projects built from my designs. If you would like to send me a few pics of your build I can pass them on to him to incLude in his gallery:

EzGallery

Cheers

Ian
 
I am glad you like it. My friend Pierre hosts an independent gallery of people's projects built from my designs. If you would like to send me a few pics of your build I can pass them on to him to incLude in his gallery:

EzGallery

Cheers

Ian
Absolutely! I’ll do a couple shots with my real camera and email them to you.
Best,
Clint
 
I'm going to be done with this soon. What does the "H"s mean on the toggle PCB?
I had no recollection of that so I had to go and look at the PCB. It is on the mic, line and out Molex 3 pin connectors. It was probably meant to indicate hot but it is in the wrong place for that. My 'standard for 3 pin Molex connectors carrying balanced signals is pin1 screen, pin 2 hot and pin 3 cold, just like an XLR. I always make pin 1 of a connector have a square pad, the the H's are beside pin 3 which is wrong. So best just ignore it. (I may have added them as a visual aid when tracking the PCB to make sue the did not get swapped between input and output).

Cheers

Ian
 
I had no recollection of that so I had to go and look at the PCB. It is on the mic, line and out Molex 3 pin connectors. It was probably meant to indicate hot but it is in the wrong place for that. My 'standard for 3 pin Molex connectors carrying balanced signals is pin1 screen, pin 2 hot and pin 3 cold, just like an XLR. I always make pin 1 of a connector have a square pad, the the H's are beside pin 3 which is wrong. So best just ignore it. (I may have added them as a visual aid when tracking the PCB to make sue the did not get swapped between input and output).

Cheers

Ian
Aha! I’ve been scratching my head about why my tube mic was out of phase to the others. Easiest fix ever :)
 
I just finished testing my build. Works great outside of the enclosure so I'm going to finish dressing it up and I'll post pics later.

Also, I have the old PCB's, anyone got a work around to get an LED indicator to work for the 48v? Can I do just add a wire to the backside of the 48v switch and call it a day?
 
Last edited:
If you have the original version of the 4toggles PCB then I think it switches after the pair of 6K8 resistors so there is no mod to add a 48V LED. There is now a new version of the PCB that does allow the addition of a 48V LED. The Gerber files are open source and available from my web site in the OpenSourcePCBs folder under the DIY tab:

Custom Tube Consoles - DIY

You can get five of them made for as little as $2 from JLCPCB.com I have attached the Gerbers zip file.

Cheers

Ian
 

Attachments

  • 4TLED..zip
    12.7 KB · Views: 1
I was having no trouble until I drilled out the body for the build. Now I'm getting thin treble-y output. There seems to be only 3 ohms between positive, negative, and ground on the output, and only 10 ohm between positive and negative before the input transformer. I've been testing the wiring but it all seems good. Something got loose 😭

I'll re-check wiring when the new switch pcbs come in, but upsetting nonetheless
 
Last edited:
I am guessing by positive and negative you mean hot and cold. Between the hot and cold output there should be quite a low resistance; it is just the dc resistance of the transformer winding. Actual value depends on which output transformer you are using. There should be no connection at all between hot or cold and ground. If you measure a low resistance like 10 ohms then something is wired wrong.

Cheers

Ian
 
Still having trouble since putting it in an enclosure. Convinced it's a grounding problem. Anyone have any ideas where I might be going wrong? I'm using the DI and the only difference other than the enclosure is I put in a better pot as the old was PCB pin that I was rigged up.


Update: Something must've happened to the output transformer as it has no resistance across the primaries. I've found the culprit. It's behaving well now.
 
Last edited:
When you say the output transformer has no resistance across the primaries do you mean it is open circuit or short circuit??

Cheers

Ian
 
EDIT: It's working. Just had a weird experience which ended up being screws on my chassis just barely grazing an exposed piece of the switch and causing fuses to blow up lol oops. It sounds so great.

Ryan
 

Attachments

  • 16626844444939208241284568121979.jpg
    16626844444939208241284568121979.jpg
    1.4 MB · Views: 1
Last edited:
When I use phantom power, I get some loud white noise on my condenser for about 3 seconds. It makes the sound again when I turn phantom off. It doesn't do that on other preamps. Is this reason for concern?
 

Latest posts

Back
Top