can you test just Mu, applying power and just for several seconds - connecting fat wire (going to lower pcb/SIT Drain) to GND, while having DM connected to observe Iq?
which pucks are you having in Mu?
if you did remove pcb from puck, zener is all yours to check with diode test of DMM
there needs to be mid connected with one outer pin
What I have done in the past to test the Mu part of the amp is to connect my 8R heatsinked test load (2 - 4R 50W resistors on a heatsink) that I use for amplifier testing to the Mu output and Gnd and measure the voltage drop across it. I usually do a Dim Bulb Test first though.
pretty much part of normal thought process - every assumption is valid, until confirmed positive or negative
🙂
🙂
Thanks all. I will test the puck, when I pulled the boards off last night it got me questioning if I received the right part. They were ordered from rs components a year or so ago when no one else had them in stock. now that mouser has them again, ordered another pair, but will test what I have while waiting.
Just un bolted them, and while smudged, pretty sure I got myself a pair of DSEI2X31-06C diodes... grrr... sorry for wasting everyone's time. Checked my invoice and I did order the right FET from RS, last time I use them,
To be honest, i have been thinkin a lot lately:
How much voltage bump up do i dare as a n00b, because it seems by guidance of the curves that the Tokins surely could like it 🥰
I really, actually dont need more Watts, but you know…
So. Say 400- 600VA per channnel.
50 volts, 55 volts, 60 volts…
…65 volts Toroidy before rectification.
Yet More??? 😎🎸
Less? Middle? Lower? Much higher???
How much voltage bump up do i dare as a n00b, because it seems by guidance of the curves that the Tokins surely could like it 🥰
I really, actually dont need more Watts, but you know…
So. Say 400- 600VA per channnel.
50 volts, 55 volts, 60 volts…
…65 volts Toroidy before rectification.
Yet More??? 😎🎸
Less? Middle? Lower? Much higher???
Amazing what the right part does! First channel up and running.
Had to adjust R1 on mu board to get Iq measurement to 460mV. But can't get drain voltage on SIT below 40V. If i understand correctly, I need to increase R11 on SIT board to 3-4K?
My U+ is about 64V loaded. Little concerned about IRF510 temp. Running about 20 mins and heard a POP... shut it down and inspected, nothing obvious on either board, let it cool, fired back up and everything works, voltages all as before. Not sure what to think but it makes music on shop speakers!
Damn buzzing Antek transformer again though... Built 3-4 amps with them dead quiet, last few all buzz...
Had to adjust R1 on mu board to get Iq measurement to 460mV. But can't get drain voltage on SIT below 40V. If i understand correctly, I need to increase R11 on SIT board to 3-4K?
My U+ is about 64V loaded. Little concerned about IRF510 temp. Running about 20 mins and heard a POP... shut it down and inspected, nothing obvious on either board, let it cool, fired back up and everything works, voltages all as before. Not sure what to think but it makes music on shop speakers!
Damn buzzing Antek transformer again though... Built 3-4 amps with them dead quiet, last few all buzz...
to get output node lower, means you need to open SIT more ( less internal resistance) which means gate voltage must be more positive (less negative)
ref to sch in post #4 https://www.diyaudio.com/community/threads/the-singing-bush.349248/post-6074239 , decrease R11
say 510R or anything close to that
or just short R11, who cares
IRF510 - if you didn't put some thermal paste, do it ........ if you have bigger heatsink , replace it ....... even 2 small ones back to back are good as one bigger
ref to sch in post #4 https://www.diyaudio.com/community/threads/the-singing-bush.349248/post-6074239 , decrease R11
say 510R or anything close to that
or just short R11, who cares
IRF510 - if you didn't put some thermal paste, do it ........ if you have bigger heatsink , replace it ....... even 2 small ones back to back are good as one bigger
Turns out the circuit works just fine if you adjust the right trimmer...
Had a pad on IRF510, swapped for paste, don't have another sink that will fit that space. Gonna run this channel for a few hours, then try to fire up the other one.
Thanks again for all the help!
Had a pad on IRF510, swapped for paste, don't have another sink that will fit that space. Gonna run this channel for a few hours, then try to fire up the other one.
Thanks again for all the help!
Been running in the shop system with lid on all morning, rock steady on Vds and Iq both channels, dead silent on cheapy speakers. Heatsinks only mid 40s, IR gun right at IXYS = 60C, THF = 50C, 510 = 60C. So may still look to see what I can fit heatsink wise on 510. It all sounds good so far. Will let it run all day, then shut it down and move it (no easy feat, got to be close to 100 lbs) over to where I can do some distortion measurements.
Thanks again, appreciate the customer support even for those of us not so smart! 🙂 Still have parts for a Bablefish JX in the shelves, need to decide if I make investment in cases. Maybe one other 25W amp, then I think I have enough amps! Never enough though 🙂
Thanks again, appreciate the customer support even for those of us not so smart! 🙂 Still have parts for a Bablefish JX in the shelves, need to decide if I make investment in cases. Maybe one other 25W amp, then I think I have enough amps! Never enough though 🙂
510 is good with 60C, no biggie
heatsinks I sent are good enough, as long there is thermal paste applied ...... and not completelly unnecessary isolation pad
if you're not happy with that, you can insert piece of 40mm long Al or Cu, mm or 2 thick, in between IRF and hsnk; goop again
it'll put it down to 50C
edit: don't trust IR gun too much; always check with your reference measuring equipment:
heatsinks I sent are good enough, as long there is thermal paste applied ...... and not completelly unnecessary isolation pad
if you're not happy with that, you can insert piece of 40mm long Al or Cu, mm or 2 thick, in between IRF and hsnk; goop again
it'll put it down to 50C
edit: don't trust IR gun too much; always check with your reference measuring equipment: