well normaly they shouldn´t get hot at all, maybe a little warm.
I use 30 AC transformers so that means around 42 volts after the bridge and caps so the voltage drop is around 12 volts.
current draw should be 20ma (10ma for each IRF Mosfet).
if only the 317 runs hot and not the 337 than the problem is either the PSU itself (maybe a short or bad component or somewhere in the circuit).
audiojoy I do have some boards left.
I use 30 AC transformers so that means around 42 volts after the bridge and caps so the voltage drop is around 12 volts.
current draw should be 20ma (10ma for each IRF Mosfet).
if only the 317 runs hot and not the 337 than the problem is either the PSU itself (maybe a short or bad component or somewhere in the circuit).
audiojoy I do have some boards left.
Hi promitheus!
I have sent you an email too, currently I´ve built the first stage of the D1 linked (AC-coupled) with an B1 buffer (and an NOS-TDA1541S1 in front of them), and I would like to compare this with the original design.
Please give me feedback if there are some of your boards left, I would like to buy one.
thanks, Michael
I have sent you an email too, currently I´ve built the first stage of the D1 linked (AC-coupled) with an B1 buffer (and an NOS-TDA1541S1 in front of them), and I would like to compare this with the original design.
Please give me feedback if there are some of your boards left, I would like to buy one.
thanks, Michael
I use the same transformer.promitheus said:
Not sure the PSU itself is the issue (tho' that's what took the hit -- esp. the 317 reg -- when I had a short in the power-connecting wiring between the PSU and the IV; I replaced the 317, but new one gets v. warm after about 10min -- its being asked to output 37mA).
As noted earlier: when I disconnect the IV, the 317 runs fine. Also, the IV sounds fine (haven't 'scoped it out or taken any detailed measurements, tho').
Well, after all this checking and testing and such, there's not much choice about what to do - either strip out all the parts and start from scratch, put a big heat sink on that poor suffering 317, or try a different power supply -I suggest a discrete reg as they usually sound better on this unbalanced version of the D1 o/p stage.
Re: IRF610 substitute for better performance?
You could try to keep the first stage with the IRF610, and implement the second stage with J-FETs, similar to the Firstwatt B1 Buffer. In my opinion, this is a huge step forward, but I still have to compare this with Promitheus boards and the original circuit.
However, this modification does not fit onto the PCBs and is a circuit change...
hollowman said:
You could try to keep the first stage with the IRF610, and implement the second stage with J-FETs, similar to the Firstwatt B1 Buffer. In my opinion, this is a huge step forward, but I still have to compare this with Promitheus boards and the original circuit.
However, this modification does not fit onto the PCBs and is a circuit change...
Hollowman, good to see you taking an interest in this one.
For different components and "better" sound (!) there has been some variations of this basic D1 unbalanced o/p stage.
Spencer did a good one that replaced the Fets with Jfets and added a CCS and a few other details - it had the same basic sound of the D1 but has slightly "finer" sound, perhaps you could call it a "Lighter" sound but is less "analogue". Sorry for the vague terms, but is a bit hard to describe the difference without getting into "babble".
On a lot of tracks, I find the Fet version with silver ICs to be a very laid back, but detailed sound that is extremely easy to listen to for long periods. Two lower mids are a bit heavier and this gives the Fet version a notable sense of rythm (or pace) that the Jfet version doesn't have. This is better with Styrene filter caps and bipasses.
The Jfet version on silver ICs is a bit brighter, more detailed and "faster" sound, well defined sound stage, etc, but on "hard" recordings/pressings, comes out too bright and I use the copper ICs for it. I tried it on a 4 x oversampling dac and had to alter the filters slightly for my taste.
The kit from Spencer included a rather good series regulator, and this adds to the difference in the 2 O/P stages.
The larger the transformer the better - I have an 50VA torroid for this and will probably upsize this when the shunt regs are ready - it makes a large difference for few dollars.
Hope some of this is useful. Again, "horses for courses".
For different components and "better" sound (!) there has been some variations of this basic D1 unbalanced o/p stage.
Spencer did a good one that replaced the Fets with Jfets and added a CCS and a few other details - it had the same basic sound of the D1 but has slightly "finer" sound, perhaps you could call it a "Lighter" sound but is less "analogue". Sorry for the vague terms, but is a bit hard to describe the difference without getting into "babble".
On a lot of tracks, I find the Fet version with silver ICs to be a very laid back, but detailed sound that is extremely easy to listen to for long periods. Two lower mids are a bit heavier and this gives the Fet version a notable sense of rythm (or pace) that the Jfet version doesn't have. This is better with Styrene filter caps and bipasses.
The Jfet version on silver ICs is a bit brighter, more detailed and "faster" sound, well defined sound stage, etc, but on "hard" recordings/pressings, comes out too bright and I use the copper ICs for it. I tried it on a 4 x oversampling dac and had to alter the filters slightly for my taste.
The kit from Spencer included a rather good series regulator, and this adds to the difference in the 2 O/P stages.
The larger the transformer the better - I have an 50VA torroid for this and will probably upsize this when the shunt regs are ready - it makes a large difference for few dollars.
Hope some of this is useful. Again, "horses for courses".
Re: Re: IRF610 substitute for better performance?
Back to the IRF610, the thing I noted was its economics -- it's the least-expensive MOSFET in this table. Not sure it was chosen for the D1 IV for cost reasons. If it was was, an upgrade is only a few cents away. Correct -- or are there other factors to consider?
I'm not familar with FirstWatt B1 (can you throw a link to the ref.).mstr said:
Back to the IRF610, the thing I noted was its economics -- it's the least-expensive MOSFET in this table. Not sure it was chosen for the D1 IV for cost reasons. If it was was, an upgrade is only a few cents away. Correct -- or are there other factors to consider?
I don't know what "silver ICs" are??jameshillj said:
Using 4x here, too. Can you elaborate on "alter the filters..."
Speaking of which, does one get best results from the Promethius (or any D1) IV by "simply" throwing it in after the DAC IC? Or is there much to be gained by playing with analog filtration (or lack of) above and beyond the default D1 IV ckt? E.g., earlier I alluded to the use of a servo to get rid of the output caps.
H'man,
Next thing to S'man!
About the 610's - from what I understand, this unit has the best compromises of the whole family - same with the IRFP240s - not a matter of cost. The early Pass preamps used these and this gave them their characteristic sound (plus the cct, naturally) - there is something about the old P1.7 preamp that just sounds really nice, regardless if it's Mahler, Lambada or P.Floyd.
As mstr has said, you could replace some of the Fets with Jfets and change the sound quite a bit and not have to change the brd much, but I'd be a bit more inclined to use Jfet in the first position and leave the 610 Fets as the output.
Also, with Spencers all Jfet version, the Current source at the front end that replaces the resistor from +ve rail will have quite a bit to do with the sound change - it generally makes the sound "dryer" (vague again, sorry) - not trying to be complicated, but to expand on thoughts about differences of Fets to Jfets. [Spencers kits are in the vendor's Bazaar as NP D1 with enhancements]
I prefer the sound of the Elna Silmics to the Panasonics, but take quite a while to "come good" - about same price, but bit bigger.
I prefer the old EI transformers and line noise "traps" etc, but looking to find suitable R-Core from China to try, rather than Torroid - doubt that it's a big difference as will end up with a Salas shunt reg here anyway - just curious, really.
Don't like chokes in power supplies (even air wound) but looking forward to trying a "gyrator" instead of choke for anode resistor in valve buffer/crossover (heretical stages)
Sorry about the "Silver ICs" - just Silver wired Interconnects - I have settled on some "Yarbo" silvers interconnects - not too dear, and maybe not the best but a well balanced sound for my ears. The copper ones are made up with some of Denis Moorecrofts Wire (DNM Audio in England) for very clear sound, esp mids/tops, or some plain copper ones with van den Hull copper in it - heavier bass and "tempo" (not again!)
I prefer the 1541A running NOS, even on the D1 - I couldn't get the sound right with the 7220 chip in circuit, even mucking about with the filter caps in the D1 - has a "grain" or "roughness" in thge sound that I couldn't get rid of - Spencers Jfet ccts brought it out even more, and first, just bipassed the chip for NOS (better)and later removed it and used a seperate clock (another improvement)
I've only used the D1 directly connected to the 1541A chip (and no extra other filters) - the original design was mated up with the PCM63 dac chip and other folks have had exceptional results with this, too.
Incidently, excuse my usual rambling on, I noticed much talk about using transformers in the signal line (again) and this time, I actually took some notice - funny how some of the old preconceived ideas just stay fixed there. I'm now thinking that there IS much merit in this and once again, "simpler can often be better".
For now ...
Next thing to S'man!
About the 610's - from what I understand, this unit has the best compromises of the whole family - same with the IRFP240s - not a matter of cost. The early Pass preamps used these and this gave them their characteristic sound (plus the cct, naturally) - there is something about the old P1.7 preamp that just sounds really nice, regardless if it's Mahler, Lambada or P.Floyd.
As mstr has said, you could replace some of the Fets with Jfets and change the sound quite a bit and not have to change the brd much, but I'd be a bit more inclined to use Jfet in the first position and leave the 610 Fets as the output.
Also, with Spencers all Jfet version, the Current source at the front end that replaces the resistor from +ve rail will have quite a bit to do with the sound change - it generally makes the sound "dryer" (vague again, sorry) - not trying to be complicated, but to expand on thoughts about differences of Fets to Jfets. [Spencers kits are in the vendor's Bazaar as NP D1 with enhancements]
I prefer the sound of the Elna Silmics to the Panasonics, but take quite a while to "come good" - about same price, but bit bigger.
I prefer the old EI transformers and line noise "traps" etc, but looking to find suitable R-Core from China to try, rather than Torroid - doubt that it's a big difference as will end up with a Salas shunt reg here anyway - just curious, really.
Don't like chokes in power supplies (even air wound) but looking forward to trying a "gyrator" instead of choke for anode resistor in valve buffer/crossover (heretical stages)
Sorry about the "Silver ICs" - just Silver wired Interconnects - I have settled on some "Yarbo" silvers interconnects - not too dear, and maybe not the best but a well balanced sound for my ears. The copper ones are made up with some of Denis Moorecrofts Wire (DNM Audio in England) for very clear sound, esp mids/tops, or some plain copper ones with van den Hull copper in it - heavier bass and "tempo" (not again!)
I prefer the 1541A running NOS, even on the D1 - I couldn't get the sound right with the 7220 chip in circuit, even mucking about with the filter caps in the D1 - has a "grain" or "roughness" in thge sound that I couldn't get rid of - Spencers Jfet ccts brought it out even more, and first, just bipassed the chip for NOS (better)and later removed it and used a seperate clock (another improvement)
I've only used the D1 directly connected to the 1541A chip (and no extra other filters) - the original design was mated up with the PCM63 dac chip and other folks have had exceptional results with this, too.
Incidently, excuse my usual rambling on, I noticed much talk about using transformers in the signal line (again) and this time, I actually took some notice - funny how some of the old preconceived ideas just stay fixed there. I'm now thinking that there IS much merit in this and once again, "simpler can often be better".
For now ...
I replaced the IRF610s, one-by-one (taking current measurements after each replacement). I ended up replacing all four, but the current draw on the (+) rail is still 36.5mA.promitheus said:
I also DMM-ck'd many other components on both the PS and main boards. They all ck'd out "fine."
I installed a larger heatsink on the 317 to better protect it; as a result, it now only runs moderately warm.
jameshillj:
As far as PS options, I'm going to implement a modified version of the Tracking Pre-Regulator...
I've used something like this before, with good success. It's easy and cheap to implement. Not sure how it ultimately compares to better shunts and all-discrete jobs, tho'.
Attachments
Could a 25 AC Volt Trannie be used?
I have a 25 AC Transformer at my disposal.
Could I use it for the Promethius powersupply?
25 AC would result in approximately 35 DC. Is a 5 Volt voltage drop enough to drive the LM 317 and LM 337? (It would make these regulators get less warm, I guess).
Please advice me.
Best wishes,
Lucas
I have a 25 AC Transformer at my disposal.
Could I use it for the Promethius powersupply?
25 AC would result in approximately 35 DC. Is a 5 Volt voltage drop enough to drive the LM 317 and LM 337? (It would make these regulators get less warm, I guess).
Please advice me.
Best wishes,
Lucas
Yeah, H'man.
It works pretty well as is - perhaps you can vary the current thru the o/p buffer for to change the sound quite a bit but wouldn't change much about the first one, unless you want to try a jfet there.
I think mstr has done it the other way round with the fets first and the jfet as the o/p buffer and reported excellent results - it's so simple to play with BUT do adjust the zero volts each time before connecting to the dac chip pins
Now about those LM317 things - if you can see your way past these onto any of the discrete regulators, even the humble zener Cmultiplier reg, will open the sound up and amaze you, and there is a tremendous freedom to change the caps, diodes, snubbers, etc in the power supply, for truly big improvements to this rather simple but exceedingly clever peice of engineering.
Other things to try - the above mentioned Salas shunt (just hard wire it on perfboard), the CTC (Charge Transfer and Cmultiplier) pre-reg supply found on the "ultimate 1541A NOS Dac thread, tuning the transformer windings (seen on the Promitheus site) Lightspeed vol control and/or B1 buffer (with +/- rails, silver wire (yeah, does make a difference!), etc, etc
P/S Caps - the usual Pana FCs, the Silmics, the Mundorfs, and the Nichicons too. They all have a degree of difference but also use discrete shottky diodes, not block bridge units - ghastly edge to sound.
Interesting, yes?!
Lucas,
don't get too concerned about " writing off" a bit of voltage - suggest a bigger heatsink - it's not a rule but often more current, rather than less, thru these things gets a better sound, and maybe bigger, better caps - don't stint here..
It doesn't take much extra effort to do a discrete reg - simple ones seen on Choky's site, for example, that work very well indeed. Big difference here at the front end.
It works pretty well as is - perhaps you can vary the current thru the o/p buffer for to change the sound quite a bit but wouldn't change much about the first one, unless you want to try a jfet there.
I think mstr has done it the other way round with the fets first and the jfet as the o/p buffer and reported excellent results - it's so simple to play with BUT do adjust the zero volts each time before connecting to the dac chip pins
Now about those LM317 things - if you can see your way past these onto any of the discrete regulators, even the humble zener Cmultiplier reg, will open the sound up and amaze you, and there is a tremendous freedom to change the caps, diodes, snubbers, etc in the power supply, for truly big improvements to this rather simple but exceedingly clever peice of engineering.
Other things to try - the above mentioned Salas shunt (just hard wire it on perfboard), the CTC (Charge Transfer and Cmultiplier) pre-reg supply found on the "ultimate 1541A NOS Dac thread, tuning the transformer windings (seen on the Promitheus site) Lightspeed vol control and/or B1 buffer (with +/- rails, silver wire (yeah, does make a difference!), etc, etc
P/S Caps - the usual Pana FCs, the Silmics, the Mundorfs, and the Nichicons too. They all have a degree of difference but also use discrete shottky diodes, not block bridge units - ghastly edge to sound.
Interesting, yes?!
Lucas,
don't get too concerned about " writing off" a bit of voltage - suggest a bigger heatsink - it's not a rule but often more current, rather than less, thru these things gets a better sound, and maybe bigger, better caps - don't stint here..
It doesn't take much extra effort to do a discrete reg - simple ones seen on Choky's site, for example, that work very well indeed. Big difference here at the front end.
Forgot to add,
As you're committed to the LM317,337 regs, suggest adding what used to be known as the "Carlos fm" power supply snubbers at the output of the supply/input to D1 cct.
From memory, you add a 100nf across each rail to ground [/U]plus a 100nF + 1Ro series resistor in parallel to this as a 2 part snubber - works like a charm - the gain clone amp folks use it a lot and highly recommended you play about with the values a bit - use good PP, or better, type caps.
Hope the colour and underline things work - if not, please excuse attempt at simplicity!
As you're committed to the LM317,337 regs, suggest adding what used to be known as the "Carlos fm" power supply snubbers at the output of the supply/input to D1 cct.
From memory, you add a 100nf across each rail to ground [/U]plus a 100nF + 1Ro series resistor in parallel to this as a 2 part snubber - works like a charm - the gain clone amp folks use it a lot and highly recommended you play about with the values a bit - use good PP, or better, type caps.
Hope the colour and underline things work - if not, please excuse attempt at simplicity!
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