Easy fix. I actually had not turned the POTs down enough. All of the adjustment is at the very low range of the 5K POTs. I thought I had turned beyond the limit but I had not. Watching the V varying into the Darlington as I turned the POT clued me. All is good.
Runs hot. I can touch the big sink for about 5 seconds. I would guess that is by design?
On to the Pumpkin...
On to the Pumpkin...
I presume you didn't connect load to Shunty ?
that means - when you connect it , it will load some heat off , too
that means - when you connect it , it will load some heat off , too
Correct. Cookbook even says to use two 470/5w. 🙂Every time I read the cookbook, new details reveal themselves!
ZM,
While I have been able to eliminate the DC offset the attenuator still behaves erratically. I'm only persisting with the Twisted Pair attenuator because the I built the preamp case with the TP attenuator in place. The tests I've tried seem to show no fault with the volume control. Is it possible that there is another reason for the dips and pops?
Thanks
Rick
While I have been able to eliminate the DC offset the attenuator still behaves erratically. I'm only persisting with the Twisted Pair attenuator because the I built the preamp case with the TP attenuator in place. The tests I've tried seem to show no fault with the volume control. Is it possible that there is another reason for the dips and pops?
Thanks
Rick
put caps between attenuator and Pumpkin , just for test
if dips and pops vanish , there is still problem with DC transposed from output to input via feedback net
if dips and pops stays ....... we'll think further ..... 😉
if dips and pops vanish , there is still problem with DC transposed from output to input via feedback net
if dips and pops stays ....... we'll think further ..... 😉
Thanks Zen, I have already put caps (2.2 uf) in and the resistors. There was a significant drop in DC with the resistors but not much more benefit with the caps. The pops and dips were still there with the caps so I took the caps back out now and left the resistors in.
Thanks generg, already looked there. 2 different sources with little DC from them and some results through the Pumpy.
if you're having pops'n'clicks with caps between att. and Pumpie , culprit isn't in Pumpie
you can blame it for sparow's fart sensitivity , but that's good thing
try attenuator for pops'n'clicks with some other gain stage or without
you can blame it for sparow's fart sensitivity , but that's good thing
try attenuator for pops'n'clicks with some other gain stage or without
I've got the same attenuator in my Aleph P 1.7 clone with no issues. I've swapped the relay boards and tried a different control board. Same results. Very frustrating because the sound is soooo good with the pair of F4 clones I've built.
try 47K bleeder resistors right after input caps
so cap- 47K to gnd - 10K Pumpie input resistor
so cap- 47K to gnd - 10K Pumpie input resistor
Was the attenuator combined with the Aleph P at the output or input?
When it was at the input, the Aleph has as you know a very low input impedance.
You could imitate this with a 10k to the ground after the pot.
Would be interesting if the clicks disappear then.....
Good point generg. I have the attenuator at the output on the Aleph P1.7, as per Papa's instructions.
I'm hoping Twisted Pair can advise if there is a possible glitch in the programing but it seems unlikely.
I'm afraid I may just have to change the volume control to something else.
I'm hoping Twisted Pair can advise if there is a possible glitch in the programing but it seems unlikely.
I'm afraid I may just have to change the volume control to something else.
Thanks for the encouragement ZM. I will reinstall the caps and shunt them to ground to see. But in the end I'd rather a simple solution of choosing another volume control rather than fighting to make the Twisted Pair attenuator work.
Ok, I've put the caps back in along with the 47k shunt resistors. The pops and dips are still there. The pops are slightly muted but still there.
are you comparing it with Aleph P , with engaged input (gain , sort of ) attenuating , or with same disengaged ?
never mind - I just came back and re-read what you answered to Generg
unfortunately , I think - in that arrangement , you'll always hear ticks and pops - having that attenuator at input of preamp
with lesser input impedance (loading of attenuator shunted to gnd , in fact ) pops will be decreased
however , with caps in between , pops are having nothing with Pumpie itself
never mind - I just came back and re-read what you answered to Generg
unfortunately , I think - in that arrangement , you'll always hear ticks and pops - having that attenuator at input of preamp
with lesser input impedance (loading of attenuator shunted to gnd , in fact ) pops will be decreased
however , with caps in between , pops are having nothing with Pumpie itself
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