cgmason1986 wrote: ↑Sun Aug 15, 2021 2:46 pm
*EDIT* no idea what happened - didn't change anything but now it seems to be working?? Maybe there was a short somewhere?
Great!
Most likely there was a short, considering that voltage dropped from 6V to 0.2V.
markusw wrote: ↑Sun Aug 15, 2021 2:57 pm
Does the heater voltage also dop to 0.2V with another tube?
Can you measure resistance from pin 9 to GND with and without tube, both power supply off?
Are you 100% sure that you did not mix up any pins on the tube socket? Sorry for asking.
I can never be 100% sure about anything haha it's fine to ask. It works now. I'm not quite sure what was going on, but I'm thinking maybe a wire was grounding on my standoffs because when I had it off the standoffs it started working. I redid the pin wiring to make sure it doesn't short, hooked it up and I'm good to go! Thanks so much for your help on this.
Maybe switch over to 12 VDC power supply. And get your heatersupply from there. I do the same.
+ to pin 4, - to pin 5 and you're done. leave pin 9 unconnected.
BTW love your design, looks great.
I made a Suhr PT15 clean channel in a box, very similar.
So I'm finishing up another build and I'm getting some weird noises when I dime the treble pot and gain pots together this time. It also seems worse when the bright switch is engaged (far right switch in 2nd video). This is the third one I've made and first time I've had this problem. The only thing I did differently this time was add a switch to connect pins 1 and 2 of the mid pot or pins 1 and 2 of the bass pot (left switch in 2nd video). I tried switching out the cap on the bright switch, swapped tubes, tried to run a wire between gain and treble pots instead of a straight bus wire in case I had too many perfectly parallel wires causing some interference, but didn't seem to work. Any ideas? It sounds great otherwise. See videos below.
Reeltarded wrote: ↑Sat Sep 25, 2021 9:27 am
What does it do with the bottom installed?
It sounds FANTASTIC!
Any stoppers on first and second grid... I can't see. I have a pedal that very specifically picks up japanese naval chatter. Used it on a record once.
Thanks for the response! Same thing happens with the back installed. I've attached the schematic I followed. It looks like first grid has a 22k stopper and grid 2 a 220k and 500pf in parallel, would that count as a stopper? I've built two others like this without issue.
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Reeltarded wrote: ↑Sat Sep 25, 2021 12:52 pm
If the small cap on the input doesn't kill the drill, lets add a grid stop (10-33k) on second grid and scrap the input cap thingy.
Red line. Right on the socket.
5194C1F5-6629-4725-A022-2F8CC0C61C38.jpeg
The input cap didn't have an effect - but I put a 22k grid stop on the 2nd grid and that definitely helped a lot! Now I'm able to max the treble and gain without feedback, but when i max the mids with the mid-boost on it still does the same thing.
For the grid stop on the 1st grid - the resistor is connected right to the input and then about 8" of wire to the foot switch then wire to the socket, would it be better connect the resistor straight to the socket and run wire to the input?
Hearing your thing made me dig around for an Alembic F2B channel a friend made for me a long time ago. After futzing around with a dirty pot I subbed it into my rig as the clean channel. I only used it to drive other amps before now, maybe to record bass a couple times..
Wow. I just knocked 80lbs off my rig. That means I can add 80lbs!
I see a racked SSS in my future.
Signatures have a 255 character limit that I could abuse, but I am not Cecil B. DeMille.
Reeltarded wrote: ↑Sun Sep 26, 2021 9:56 am
Hearing your thing made me dig around for an Alembic F2B channel a friend made for me a long time ago. After futzing around with a dirty pot I subbed it into my rig as the clean channel. I only used it to drive other amps before now, maybe to record bass a couple times..
Wow. I just knocked 80lbs off my rig. That means I can add 80lbs!
I see a racked SSS in my future.
Hahaha congrats, these little preamps are awesome aren't they? I want to do an ODS and SSS next.
