look at the Old thread Dac End #1970, there is the offer of Bud, I´m not good in making links, sorry
Hi Quanghao,
I am in the midst of building and testing the DAC board. of the 6 regulators, i can adjust the voltage to +5/-5 except for one where I can manage to get 3.85V no matter I turn the trim pot (1K).The led string is lit. The AC is 9v about 10.6 w/o load and dc at diode is 13.6. anu idea what could be wrong ? thanks
I am in the midst of building and testing the DAC board. of the 6 regulators, i can adjust the voltage to +5/-5 except for one where I can manage to get 3.85V no matter I turn the trim pot (1K).The led string is lit. The AC is 9v about 10.6 w/o load and dc at diode is 13.6. anu idea what could be wrong ? thanks
Found these at http://www.selectronic.French supplier
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Bud P FINALLY replied to my email (after having to send 3) and said that he'd get back to me on Friday and today is Friday... Only problem is that he was supposed to get back to me LAST Friday... I've been patient but if it's this hard to give someone your money just imagine how hard it's going to be if you ever have a problem or need support.
Antek - Is really a GREAT option! I've dealt with them in the past and purchased a good 20 transformers from them and never a single problem. They're always ready to answer questions, sell you products and provide support! As a bonus Antek is also the same company as PAR Metal and they can also supply you with a case for this project, saving time and minimizing shipping costs and best of all aggravation.
I'm starting to wish I had called Antek 3 weeks ago... I'd already have my transformers in hand and I'd be listing to this DAC by now instead of just looking at it!
Antek - Is really a GREAT option! I've dealt with them in the past and purchased a good 20 transformers from them and never a single problem. They're always ready to answer questions, sell you products and provide support! As a bonus Antek is also the same company as PAR Metal and they can also supply you with a case for this project, saving time and minimizing shipping costs and best of all aggravation.
I'm starting to wish I had called Antek 3 weeks ago... I'd already have my transformers in hand and I'd be listing to this DAC by now instead of just looking at it!
Hi everyone,
I have finally managed to put to rest all of the alligators that have been in my way over the last 4 weeks and can turn to something that interests you. Pharod's first transformer has been laminated and tested and will be corrosion proofed over the weekend. This is a process that takes 4 days to cure. Then the assortment of pieces you see in the picture below will be put to good use.
Having located all of the materials squirreled away 15 years ago, when the Mackie 3204 mixing console was finally removed from the market, I can now actually offer a finished product. The pieces you see below are a power transformer with the primary set for 120 volts AC, core flux density of 8 KG using M6 core material and no load to full load regulation of 2%. Safety agency approval, as a professional product, under CE 6500 is the build standard. This means no one shot thermal fuse, but full creepage and clearance and 3500 volts dielectric withstand primary to secondary and core.
The rectangular metal sheet is an M6 core suppression band, the strip of copper is mounted around the coil and up over the core suppression band and the whole thing fits into the end bells and channel frame shown. The secondary leads will be separated out, by winding, with pieces of shrink tube. This is the $90 transformer, and now you know why.
I have what I consider four firm orders for this transformer and we will wind the remaining three the middle of next week, with projected shipping two weeks after winding. We have a tiny sliver of time to do this in, so, if more of you than Klaus, Daniel and Quanghao want one, in anything like a reasonable amount of time, PM me this weekend. You must tell me what voltage and frequency your particular transformer needs to run under.
Bud
I have finally managed to put to rest all of the alligators that have been in my way over the last 4 weeks and can turn to something that interests you. Pharod's first transformer has been laminated and tested and will be corrosion proofed over the weekend. This is a process that takes 4 days to cure. Then the assortment of pieces you see in the picture below will be put to good use.
Having located all of the materials squirreled away 15 years ago, when the Mackie 3204 mixing console was finally removed from the market, I can now actually offer a finished product. The pieces you see below are a power transformer with the primary set for 120 volts AC, core flux density of 8 KG using M6 core material and no load to full load regulation of 2%. Safety agency approval, as a professional product, under CE 6500 is the build standard. This means no one shot thermal fuse, but full creepage and clearance and 3500 volts dielectric withstand primary to secondary and core.
The rectangular metal sheet is an M6 core suppression band, the strip of copper is mounted around the coil and up over the core suppression band and the whole thing fits into the end bells and channel frame shown. The secondary leads will be separated out, by winding, with pieces of shrink tube. This is the $90 transformer, and now you know why.
I have what I consider four firm orders for this transformer and we will wind the remaining three the middle of next week, with projected shipping two weeks after winding. We have a tiny sliver of time to do this in, so, if more of you than Klaus, Daniel and Quanghao want one, in anything like a reasonable amount of time, PM me this weekend. You must tell me what voltage and frequency your particular transformer needs to run under.
Bud
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Make sure that your trim pot is working as it should... I've had the odd bad one over the years and your symptoms are consistant with a bad trimmer or the wrong value trimmer. Just to be safe I'd replace it!
I've just tested my board and I get all the appropriate voltages and adjustments works as they should so the circuit and values are correct.
Good luck!
Finally done!! The boards anyway...
It is wonderful!
You listen to it?? Can you tell all friends and me please ??
Quanghao
No not yet... I just used a single 12 volt transformer to test each power supply one at a time but I'm still waiting on Bud P. for the transformers that will power both boards.
Just wanted to post the completed boards in case it helps others. I'll be upgrading a few caps but for now this is it!
So far these have been a very well designed boards!
Thanks Quanghao
Just wanted to post the completed boards in case it helps others. I'll be upgrading a few caps but for now this is it!
So far these have been a very well designed boards!
Thanks Quanghao
Hi Quanghao,
Need help to trouble shoot the B+ for IV board. I using 6H30 tube, transformer 200Vac. The HV regulator can set the voltage 230V without tubes in. After plug in the tubes and power on, the voltage drop to 137V when tubes heated up and cannot adjust up higher. AC in measures 216V, dc is 275V before R1 22Ohm and 248V after. The DAC-End board is fixed and all +/- 5v supply is working.
Need help to trouble shoot the B+ for IV board. I using 6H30 tube, transformer 200Vac. The HV regulator can set the voltage 230V without tubes in. After plug in the tubes and power on, the voltage drop to 137V when tubes heated up and cannot adjust up higher. AC in measures 216V, dc is 275V before R1 22Ohm and 248V after. The DAC-End board is fixed and all +/- 5v supply is working.
Maybe you used too large for the tube line 6h30, do you reduce the value of resistor R1 20 Ohm down 18-20 Ohm, you adjust the voltage up as you! You check the voltage drop in R22,21,37,38 = 200R is how much?
Yea, I just check and R1 I made a mistake was 33 ohm,too high not 22R. Voltage drop at R22,21,37,38 = 220R <- (220 is ok?) is 2.6-2.85V.
No!
R1 set current for SSHV Supply =22 Ohm, Ia ( I total ~95-100 mA)
So Iv need total= 80mA, 1/2 Triode 6h30 need 18-20mA.( the sound is the most )
And Voltage at Anode =90-100V,
So voltage at R 22, 21,37,38 =3.8-4V , and R =200-220 Ohm, it is ok!
Thanks
You see it???
I have set R1 to 20R (33//47R) and Voltage at R22, 21,37,38 =4.1-4.2, and Voltage at anode 89-90V, B+=197, should this be ok, or need to drop R1 lower to increase B+ ?
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