What about David Hasselhoff? 😂 Weekend finally here, I need to give my BA3 a tune up. Last time offset was fine. My heat sinks are quite warm, but far from hot. Figuring I might up the bias a touch. Both front end and Output stage.
Russellc
Did some quick mods today to follow up the last changes. R13 @ 230R now, making the circuit closer to stock gain after the R10 and R11 reductions to 12R a few weeks ago (both loads hence reduced but ratio remains almost the same) Also, R12 is now jumpered, and R1 reduced to 500R. First impression is gooood.
I see the source of the confusion; that's actually the slightly modified version in the F5 Turbo article.
The schematics as described in the original Audioxpress article can be found in Figure 6 here:
https://www.firstwatt.com/wp-content/uploads/2023/08/prod_f5_man.pdf
The schematics as described in the original Audioxpress article can be found in Figure 6 here:
https://www.firstwatt.com/wp-content/uploads/2023/08/prod_f5_man.pdf
Can we safely modify that resistor?
I know it was ok to do so with the f4. I think I changed that one from 47k to 200k based on a response from Nelson at some point. If it's important to someone I can check the exact value...
Hi. I"m going to build fully balanced preamplifier with two BA-3 PCB and ladder relay attenuator, controlled by Arduino.
PS would be separate for each channel, double mono.
My question is what VA ratio transformer should I take?
I found 250VA 2x18-0-18V 3.5A, and I suppose it is a little oversize for this job.
PS would be separate for each channel, double mono.
My question is what VA ratio transformer should I take?
I found 250VA 2x18-0-18V 3.5A, and I suppose it is a little oversize for this job.
I am curious to learn about your balanced relay attenuator if you are interested in sharing.
An oversized transformer won't hurt anything. I tend to go oversized as I like to swap them into different projects just for the heck of it. For instance, I swapped the transformer for a BA-3 preamp project I did to power a ACA mini recently. I am glad I went oversized on that one as it came in handy.
An oversized transformer won't hurt anything. I tend to go oversized as I like to swap them into different projects just for the heck of it. For instance, I swapped the transformer for a BA-3 preamp project I did to power a ACA mini recently. I am glad I went oversized on that one as it came in handy.
It's just a project right now. Not a real one.
I'm going to use two sets of 8 relays, each with two groups of switching contacts.
Don't know, if I could post some links here or not.
There are some online calculators for resistors values. There are some different schematics for the attenuator: one with constant input impedance and one with constant output impedance.
It would be controlled with Arduino mega, with encoder and 433Mhz remote(not sure, but may be).
I have 24V Finder relays in my junk, so I'm going to use optocouplers to operate them.
If it is interesting for you, I can share the PCB, when it would be ready.
Feel free to ask questions.
I'm going to use two sets of 8 relays, each with two groups of switching contacts.
Don't know, if I could post some links here or not.
There are some online calculators for resistors values. There are some different schematics for the attenuator: one with constant input impedance and one with constant output impedance.
It would be controlled with Arduino mega, with encoder and 433Mhz remote(not sure, but may be).
I have 24V Finder relays in my junk, so I'm going to use optocouplers to operate them.
If it is interesting for you, I can share the PCB, when it would be ready.
Feel free to ask questions.