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A Very Compact Hybrid Amp - Page 109

post #1621 of 2213
Quote:
Originally Posted by rds View Post
Unless you want to use 2 truck batteries this amp isn't going to run long.
that sounds like a dare around these parts...
post #1622 of 2213
Quote:
Originally Posted by wiatrob View Post
I've verified all component values and orientations. I've replaced the 24V reg and TLE24.

Without tube. I have looked at all the solder joints for bridges and they look good.

C1L WAS in backwards, briefly, but didn't pop and has been replaced...

I may build up another and wait to troubleshoot this one after the meet.
Heh, I had my problems as well right before the NY Spring meet - To be sure I got it going I just replace a bunch of sand.

As runeight says, there are not many parts in the amp that will cause that kind of draw & not burn or pop (thereby reducing the draw to below normal).

Your build check statements point to a bad part, but my guess would have been reversed diode or reg... Something early in the PS. I'd re-review & check from the 1st PS sand components back all the way to wallwart.

I'm w/runeight - would think only something like a short would cause & handle that kind of draw for more than a second & it would only happen once.
post #1623 of 2213
Quote:
Originally Posted by aphexii View Post
This may be out of left field (and well i'm half asleep so my brain isn't fully working), but how hard would it be to get this thing battery powered?
A re-design... Need A/C for HV multiplier & 30VDC minimum for LV & heater. Tube heater alone draws 4W or so & that's heavy. Best to look elsewhere.
post #1624 of 2213
Quote:
Originally Posted by cfcubed View Post
Your build check statements point to a bad part, but my guess would have been reversed diode or reg... Something early in the PS. I'd re-review & check from the 1st PS sand components back all the way to wallwart.
That's what I thought too - all the diodes are correct. I'll swap the 2595 (even though it's putting out proper voltage), test the diodes and trace through the PS.
post #1625 of 2213
Quote:
Originally Posted by wiatrob View Post
That's what I thought too - all the diodes are correct. I'll swap the 2595 (even though it's putting out proper voltage), test the diodes and trace through the PS.
Hey, just prior to doing that you could try lifting the load/output pins of the 24V & 2595 & using an ammeter from the pins to where they connect on PCB.

The stable draw of a CTH is usually not more than 1/2 an amp (12 watts) or so. Current draw on heater reg should be about tube heater spec (.4A?).
IIRC the LV reg draws around 6/7 watts throwing off 50%-> 60% in heat, so maybe supplying 3&1/2 watts (< 0.15A) or so?
HV shouldn't draw much at all. Could also lift input legs & see what the reg are drawing. Note: all of these are rough numbers off the top of my head

But seem like nearly 1A @ 24 VAC is being consumed somewhere and that's an awful lot. By measuring load about the regs we can split the problem to 1) prior or 2) post regs.
post #1626 of 2213
wiatrob, Suggest you do what runeright asked me to do long back when I had such problems with my proto build.

Remove the 24V regulator.

TUrn on the amp and see if any of the PSU components fry. Check for voltage at input of voltage regulator, should be about 32-34 volts.

If that seems to be fine then remove all the splitter transistors except for the TLE2426 splitter IC.
Put the regulator back in its place and turn on the amp again. Check to make sure the output of the ground splitter IC is reading 12 volts and its input is reading 24 volts.

If that is right, then install the rest of the splitter silicon and give it a try. The amp should work then.

If not, then the problem is with the buffer transistors.

Thsiis the process I have followed for 4 of my builds that gave me problems.
It has always been the splitter that needed to be replaced even though I had messed up the PSU in one build. That amp wouldn't work until i replaced the splitter section.
post #1627 of 2213
Mea Culpa. I don't listen to my advice to triple check things very well. Thanks all for the input and the edifying troubleshooting reminders.
There were no diodes in UPSIDE DOWN. but one WAS backwards - you called it Sachu.

Fixed it and the e12 trips. Checking voltages now...

I have even deeper respect for Sachu and Nux - you get a little crosseyed building multiple CTHs...
post #1628 of 2213
All voltages are SPOT ON (12V measurements are within 10mV of each other!)

Playing beautiful music. This amp will be at the meet Saturday.
post #1629 of 2213
Quote:
Originally Posted by wiatrob View Post
Mea Culpa. I don't listen to my advice to triple check things very well. Thanks all for the input and the edifying troubleshooting reminders.
There were no diodes in UPSIDE DOWN. but one WAS backwards - you called it Sachu.

Fixed it and the e12 trips. Checking voltages now...

I have even deeper respect for Sachu and Nux - you get a little crosseyed building multiple CTHs...
heh...i've learned it the hard way my friend. lost a transformer before I grew a brain and put a fuse in there .

Edit: awesome !! Now get to work on my EHHA perf top so I can get my stuff going here.
post #1630 of 2213
Quote:
Originally Posted by sachu View Post
heh...i've learned it the hard way my friend. lost a transformer before I grew a brain and put a fuse in there .
Fuses saved a lot of rework here... Russian K42 PIOs, Alps RK27, 1/4"out, front panel Red LED, Orange tube uplight. Socketed R3H for alternate/alternate heater values (currently 6.3V).



I'm on the perf top...
LL
post #1631 of 2213
Nicely done Bill...been meaning to try out those Russian PIOs but they are all sold in lots of 10 or 20 which is wasteful.

should have my obbligatos soon as well.

Btw, definitely try out the 6CG7/6FQ7.
post #1632 of 2213
I've had a 6CG& clear top for a while - didn't you see my posts. I'll drop some PIOs in your care package, should be off this week.
post #1633 of 2213
post #1634 of 2213
umm Bill... my EHHA perf top?
post #1635 of 2213
'Twas the care package I mentioned. It's right in the middle of my bench so I won't postpone any longer...
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