Schade Common Gate (SCG) Preamp
- Thread starter ra7
- Start date
Yes that one is good too.
Looks like the pitch between pins is the same but the row spacing is <1mm different. Most likely it will work.
I'm listening to STQ1NK80ZR-AP and it is absolutely fantastic.
BTW, I did buy a small quantity, so if someone is desperate, I can send them the 80ZR-AP.
This is sort of the point of this circuit--we want to get off our reliance on unobtanium parts, whether it is DHTs from the 1920s or really great modern transistors. There's so many options--some better than others--but hopefully, there will always be sufficient number of options.
BTW, I did buy a small quantity, so if someone is desperate, I can send them the 80ZR-AP.
This is sort of the point of this circuit--we want to get off our reliance on unobtanium parts, whether it is DHTs from the 1920s or really great modern transistors. There's so many options--some better than others--but hopefully, there will always be sufficient number of options.
120V to the top FET in the CCS. 100V is also okay but good to have a bit of leeway. I would shoot for 100-120V secondaries.
We need about 20V on the bottom FET, 40V on the gain (middle) FET, and the same amount across the CCS (40V), so end up with about 100V. But with 120V, you get a bit of flexibility if you plan to play with different FETs. The above distribution works for the two STQ parts.
We need about 20V on the bottom FET, 40V on the gain (middle) FET, and the same amount across the CCS (40V), so end up with about 100V. But with 120V, you get a bit of flexibility if you plan to play with different FETs. The above distribution works for the two STQ parts.
They list 1,719 in stock ATM.5 days later….. almost 4K sold out
I’ll have at least 8 pairs extra. Similar to Raul’s offer, if anyone’s desperate for a pair of STQ1NK60ZR-AP to build his preamp, I can send a few out too.
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That is exactly right.Perfect, I have a trafo just right for the job
What's the diameter and lead spacing on the pcb for the electrolytic caps in the psu section?
25mm Dia/10mm LS?
Once the PS section is in, I’ll post some measurements of noise, distortion, etc. Gain is about 20 db (or 10x) and is set by the amount of Schade feedback.
ra7,
I did see that one. I was hoping to get one with 2 secondary's, but for the cost it is a good option even purchasing 2.
This one looks like it would work. Triad VP230-760.
I did see that one. I was hoping to get one with 2 secondary's, but for the cost it is a good option even purchasing 2.
This one looks like it would work. Triad VP230-760.
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I found a used Triad Magnetics VPS230-760 on ebay and ordered one. I got it for $10, so with shipping it was $24. I figured for that price it was worth a shot.
ra7, Looking forward to hearing how the boards have worked out. They look beautiful. Nice and clean with all the critical components together.
Now I need to order the rest of the parts
ra7, Looking forward to hearing how the boards have worked out. They look beautiful. Nice and clean with all the critical components together.
Now I need to order the rest of the parts