Thanks! More newbie questions... do I need resistors or thermistors or anything of the sort on any of the grounds or anything (I do apologize if these are dumb questions but I think I see such things when I look closely at build photos)
Also what variant of dale resistors did you provide us with 6L6? Lol when I do my mouser search for some 27k... I still am left with 3 choices.... way better than 400... but the 3 choice still leaves me perplexed.
Also what variant of dale resistors did you provide us with 6L6? Lol when I do my mouser search for some 27k... I still am left with 3 choices.... way better than 400... but the 3 choice still leaves me perplexed.
The resistors are RN55 and I sort for cheapest, because they are all uniformly excellent resistors. Even the "least tolerance" of the RN55 are going to be better than 99% of any through-hole resistor available anywhere.
If you want to add a CL-60 as PSU ground lift (or the diode bridge trick like the Pearl 2) go right ahead, it's going to be worthwhile to do it.
MEPER - if you need it, go ahead. I'd be more inclined to make a power strip or similar with the DC blocker in it, but that's just me.
If you want to add a CL-60 as PSU ground lift (or the diode bridge trick like the Pearl 2) go right ahead, it's going to be worthwhile to do it.
MEPER - if you need it, go ahead. I'd be more inclined to make a power strip or similar with the DC blocker in it, but that's just me.
OK, mine is alive and playing music. Let it go for a while, its just on a board all spread out with long wires going to everything. Using an old JBL power amp and and an older set of speaks, once all is proven will move it to bigger system. Box is on the way, as is power switch and selector switch from Tubecad.
What sort of fuse should this thing use? (120 volt at wall.)
Thanks,
Russellc
What sort of fuse should this thing use? (120 volt at wall.)
Thanks,
Russellc
Darn it, camera batteries charging, warning: Not in case, just a spread out bird nest. Very quiet, no hum or anything. Clear strong sound. Ready to hook up to Aleph J and Econowaves. { JBL 4430 clone, thanks Zilch. )
Sounds good so far, source is smart phone and spotify right now. Lots of gain, B1 was doing duty here.
Russellc
Sounds good so far, source is smart phone and spotify right now. Lots of gain, B1 was doing duty here.
Russellc
Hmmm. Slight turn on thump with Aleph J I dont recall, and a little hum with 87 dB speaks. Never heard that before. Maybe only with volume all the way down is there hum. Once I turn it up at all, seems to be gone...cant hear in quiet passages, etc.
Hopefully will dissipate once boxed up and grounded?
Ruissellc
Hopefully will dissipate once boxed up and grounded?
Ruissellc
Nope, If I pause it, I can hear hum. Not extreme, but more than I have previously heard with this amp and much more sensitive speakers. Dont think I noticed this with JBL amp....Not saying it didnt, but think I would have noticed.
Put JBL amp back in, some hum as well, but less. Not used to any. Hopefully just needs to be in a box, shorter leads to RCAs, volume pot, etc.
Russellc
Put JBL amp back in, some hum as well, but less. Not used to any. Hopefully just needs to be in a box, shorter leads to RCAs, volume pot, etc.
Russellc
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Probably right. I also had more hum than I liked using an Ebay switcher with highly efficient speakers though. I installed some more filtering caps after switcher and lowered my hum to an acceptable level. I ran a wire from circuit ground to chassis ground as per all my builds. Sometimes I isolate the circuit ground to chassis ground with resistor or CL-60. Might help if you have not done so. It also sounds like your volume pot is not grounded to chassis when it hums with volume pot turned all the way down.
That’s good to know, I was worried about hitting 100ma while playing with circuit and listening to music. Another example would be to hook a AA battery to your speaker. Not really that scary.... 12V car battery and Smokey smokes.
YouTube
Thankyou, I may very well put 10uF Silmic and one of Zenmod's fav polycarbonate by passes.
I can't help but think something isn't quite right with my build. A few mv is one thing, but isn't 1.1 VOLTS another? Maybe I am over thinking this.
No further play, short of ideas to try if anyone has one, until box arrives with chassis from DiyStore.
Thanks,
Russellc
Seems to sound fine so I would really like to work this thing out. Gain is there, seems very clear without being edgy, should sound better properly grounded, hoping it's offset is more stable once in chassis as well.
May have to go with Silmic/polycarb bypass on output, but just seems if all is right with build, these things shouldn't happen.
Cleaned boards carefully twice, checked all solder joints, nothing obvious.
Darn it, anxious for that chassis!
Russellc
May have to go with Silmic/polycarb bypass on output, but just seems if all is right with build, these things shouldn't happen.
Cleaned boards carefully twice, checked all solder joints, nothing obvious.
Darn it, anxious for that chassis!
Russellc
That was Russell's statement about 1.1V output. It needs lowering as close to 0 as possible with the pots. A few millivolts either way will be close enough.