I did a quick measure tonight. I'll do something more thorough tomorrow.
Shortly after power-on, Vrail was about 34V, Vr2 and Vr3 were both about 40mV, and TP1-TP2 was about 2.5V. Like I said, I'll get more accurate measurements, and more precise time measurements, tomorrow. I was surprised to see TP1-TP2 that high that quickly (esp since this morning that was much lower on the same board in the same time frame), so I want to re-measure tomorrow. However, ~40mV implies about 8mA current. Does that seem unusual given 11.55mA Idss?
Shortly after power-on, Vrail was about 34V, Vr2 and Vr3 were both about 40mV, and TP1-TP2 was about 2.5V. Like I said, I'll get more accurate measurements, and more precise time measurements, tomorrow. I was surprised to see TP1-TP2 that high that quickly (esp since this morning that was much lower on the same board in the same time frame), so I want to re-measure tomorrow. However, ~40mV implies about 8mA current. Does that seem unusual given 11.55mA Idss?
We shoot for ~9mA final after the degeneration resistors (R2, R3) and warm up have done their business.
Looks like I'm in the right ball park then. Odd that TP1-TP2 was as high as it was, when this morning it was quite a bit lower. But we turn the heat down at night, and the house was warm when I got home tonight. I'm starting to think that I am chasing chimeras. I'll measure more tomorrow, then put the new transformer in, and mount the MC cartridge!
Me I set it once when warmed up and forgot it. Many times I just flick all switches on for the whole system and in 2 minutes I had cued a record. The system takes some time for the class A amp to come up best anyway so I don't pay much attention. If you see that your final warm up Iq is >9mA just use next higher value resistors available in no hurry. Let us know how it went with audio test.
D.Self's Trimodal does this. One of the Krell Klones had a summer/winter switch.
Yeah, thanks for the sanity-check. I tend to get a little obsessive when things aren't exactly as I expect. The proof of the pudding is in the listening, after all. I'll set the voltage for "right" when warmed up; the current looks right hot or cold. I might try a couple of experiments just to understand the circuit a little better, but now my priority will be to get it hooked up and listen to it!
Up and running, all lights lit🙂
I had problems finding high enough leds for the quads only about 7,45v
When i fired up at rail voltage @ 34v the TP1 -TP2 was -0,5V
Had to lower the rail voltage quite a bit now at apox 31,5v
I am running 10,5ma 369 and 3.3ohm R 2&3
The R2&3 voltage is about 27-27,7mv = 8,18- 8,42ma
The R13 voltage is about 21,5 -22V
Have tried to adjust the Vr1 to get more current through R2&3, have the Vr1 all the way anti clockwise getting the last mv out of R2&3
The R2&3 total (apox 54mv) is a little higher in R/H channel than L/H
Will do fine tuning when cover is one and temp has settled.
So to my Q:
Should i use Vr1 to adjust the current through the 369 and getting them equal i both channels (i know that the 369 was a tad stronger in one channel than the other)?
Is the 31.5v rail to low and should i try to get the 4 leds closer to the recommended 7,75v?
Comments?
edit: cleaned up most of the poor spelling
I had problems finding high enough leds for the quads only about 7,45v
When i fired up at rail voltage @ 34v the TP1 -TP2 was -0,5V
Had to lower the rail voltage quite a bit now at apox 31,5v
I am running 10,5ma 369 and 3.3ohm R 2&3
The R2&3 voltage is about 27-27,7mv = 8,18- 8,42ma
The R13 voltage is about 21,5 -22V
Have tried to adjust the Vr1 to get more current through R2&3, have the Vr1 all the way anti clockwise getting the last mv out of R2&3
The R2&3 total (apox 54mv) is a little higher in R/H channel than L/H
Will do fine tuning when cover is one and temp has settled.
So to my Q:
Should i use Vr1 to adjust the current through the 369 and getting them equal i both channels (i know that the 369 was a tad stronger in one channel than the other)?
Is the 31.5v rail to low and should i try to get the 4 leds closer to the recommended 7,75v?
Comments?
edit: cleaned up most of the poor spelling
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31.5V is not too low given your other measured figures. Use VR1 to balance, of course. Your 369s were measured in a hotter room temp when characterized no doubt, your results compute. Don't change the LEDs. You will see closer to 9mA when hot. Let it come up in a box first.
Thanx.
Still not as cold as normal for winter Norway but prob. colder than when Tea-bag did the matching.
Mahalia Jacksons big voice is now warming up the folded.
Looks promising
The setup is on a prototype scale, will move the raw PS out in a designated box later when design is settled.
The 50hz hum is only noticeable at full volume and it is no other hiss what so ever🙂
Runs with twisted silver in cotton from the bord and no earth, still quiet...
Thank you Salas and Tea-Bag time to move some vinyl
Observe the Hi-End lid, cardboard is known for its hi resolution and smooth sound😉
Still not as cold as normal for winter Norway but prob. colder than when Tea-bag did the matching.
Mahalia Jacksons big voice is now warming up the folded.
Looks promising
The setup is on a prototype scale, will move the raw PS out in a designated box later when design is settled.
The 50hz hum is only noticeable at full volume and it is no other hiss what so ever🙂
Runs with twisted silver in cotton from the bord and no earth, still quiet...
Thank you Salas and Tea-Bag time to move some vinyl
Observe the Hi-End lid, cardboard is known for its hi resolution and smooth sound😉
Attachments
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Very natural looking build pellesmil.
Mine is running a bit hot - 15,5C above ambient. It is in a bookshelf hidden by my CD's.
Just a few cm's of space above it. I will probably get rid of the top of the chassis and install a net (or is it called a mesh?).
Mine is playing as soon as I have a spare minute🙂.
Regards
Mine is running a bit hot - 15,5C above ambient. It is in a bookshelf hidden by my CD's.
Just a few cm's of space above it. I will probably get rid of the top of the chassis and install a net (or is it called a mesh?).
Mine is playing as soon as I have a spare minute🙂.
Regards
Pellismil what kind of signal caps are you using, they appear to match the cardboard chssis.
Good work !!!
Good work !!!
Some listening impressions,
3,3uf Mundorf ZN output cap and Jupiter HT 100nf as interstage
This is just preliminary impressions, i KNOW that the sound will change when getting some hours on it.
-first of all, it is Quiet, dead Quiet🙂
-Its smooth yet dissolved,
-The highs and the mid-tones are pleasant yet neutral not playing anything else than whats hidden in the groove
-The bass is a little fat in the 50-100hz area, (on some records)
this might be caused by several things:
-My speakers are bass reflex and some of the sound is typical bass reflex sound (yet its is not as pronounced on my BIII dac)
-I have not tested "Hi-end approved" records so some of the fault could be in the recording.
-The folded need many hours to settle and the output cap might be suspended for a Clarety cap MR
Per
3,3uf Mundorf ZN output cap and Jupiter HT 100nf as interstage
This is just preliminary impressions, i KNOW that the sound will change when getting some hours on it.
-first of all, it is Quiet, dead Quiet🙂
-Its smooth yet dissolved,
-The highs and the mid-tones are pleasant yet neutral not playing anything else than whats hidden in the groove
-The bass is a little fat in the 50-100hz area, (on some records)
this might be caused by several things:
-My speakers are bass reflex and some of the sound is typical bass reflex sound (yet its is not as pronounced on my BIII dac)
-I have not tested "Hi-end approved" records so some of the fault could be in the recording.
-The folded need many hours to settle and the output cap might be suspended for a Clarety cap MR
Per
Cool i have the same issue with my setup,
The TT (Well TT) is sitting on the side wall apox just to the left of my listening pos,
For the moment i use about 1 meter cable from the TT to the Riaa, and from there a 70 cm cable to the preamp (both components in the bookshelf on the same wall as the TT.
About 2,5m cables runs from the preamp to the power amp witch is sitting between the speakers.
I would like to put all stereo components together between the speekers and cleaning the bookshelf for both Riaa and preamp.
But i then need to run about 4metes with cable from the TT to the Riaa.
Im gonna do a test later and see if my twisted silwer in cotton cable with behave.
If the 4meer project is Nogo than am back to the drawing board.
Fitting the folded + a 600VA PS behind the records in the bookshelf might bring me into teh same problems as you have with issues getting enough cooling
You might wanna try some brass mesh, gives you good cooling and woks wonders as sheelding
Thanx.
Im have a fetish for Danish design (Not!) so neat and tidy is my middle name
Use Mundorf ZN 3,3uf for C4 and upiter HT 100nf for C3
All the ecaps are SimlicII
Good idea Per. I will test brass mesh both topp and parts of the bottom. I will also drill some holes in the shelves when the mighty one is out of the house 🙂.
What dimension is your silver wire? One or many leads? Where do you buy the sleve?
Regards
What dimension is your silver wire? One or many leads? Where do you buy the sleve?
Regards
Yea, be careful when modifying interior, the Queen of home and garden tend to have a 6th sense for monitoring ANY changes in the nest.🙄
The wire i have is 0,5mm 99.99% pure annealed (finsølv in Norwegian) , solid wire
I used to purchase from Svalander.se at about 70Skr/m not to expensive for you, i have to deal with some extra shipping and customs😡
Recently i purchased a roll of apox 60m from the Norwegian distributor ka-rasmussen.no
15,8Nok/m + 25% Vat is a treat
The coton is for sale several places but i normally get it from Svalander.
Getting the silver into the cotton is not done in 5 minutes but it is ok work when watching mindless tv series with my dear gives me double points:
making cable and earning points at home😀
Lastly i use the battery drill and twist it TIGHT,
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Thanks Per. I will test this including the tv-series when she have found the holes🙂
I probably need some points when the time comes.
Regards
I probably need some points when the time comes.
Regards
Got the break in machine started.
And old 10Kohm attenuator between the cd player and the folded.
Playing my favorite burn in CD from Hagerman with pure noise.
I guess a day or 2 with that equals many weeks with ordinary vinyl playing
And old 10Kohm attenuator between the cd player and the folded.
Playing my favorite burn in CD from Hagerman with pure noise.
I guess a day or 2 with that equals many weeks with ordinary vinyl playing
