Response to a PM from SoIL4x4
"Glad to hear you are still working on the FEs, even though you have been busy with some class A projects ...........It seems now I have a few preamp projects to work on........"
The FE is definitely still my go to amp. The discrete and TDA builds have been fun and great learning experiences, but for me, nothing yet has the "live" in the room character that comes out of the FEs. I'm still fully on-board.
BTW, I've settled on feeding the FEs with a computer through a Mini2496 DAC using JRiver Media Center playing flac (S/PDIF over a BNC cable)and other non-compressed formats. For now there is no pre and I adjust the volume from within the program. If/when I bypass the audio driver in the computer I suspect a bare pot will be all that's needed. I swear the SPL of the FEs has increased significantly with continued use. I've read that transformers can improve by responding/reforming to the internal magnetic fields and that may be the cause. It would be interesting to hear if other current FEs users have experienced anything similar.
If your library is still mainly CD based, and you want to give this a try, there are several free and low cost programs that make bit perfect conversion files from those CDs to feed the DAC. The upgrade BOM Dario created for the Mini2496 DAC is a very inexpensive and high quality solution for anyone who has yet to enter the digital domain.
P.S. - Though I've mentioned much of this before, I think I'll post part of this as others may be trying to decide whether to pre or not to pre.
"Glad to hear you are still working on the FEs, even though you have been busy with some class A projects ...........It seems now I have a few preamp projects to work on........"
The FE is definitely still my go to amp. The discrete and TDA builds have been fun and great learning experiences, but for me, nothing yet has the "live" in the room character that comes out of the FEs. I'm still fully on-board.
BTW, I've settled on feeding the FEs with a computer through a Mini2496 DAC using JRiver Media Center playing flac (S/PDIF over a BNC cable)and other non-compressed formats. For now there is no pre and I adjust the volume from within the program. If/when I bypass the audio driver in the computer I suspect a bare pot will be all that's needed. I swear the SPL of the FEs has increased significantly with continued use. I've read that transformers can improve by responding/reforming to the internal magnetic fields and that may be the cause. It would be interesting to hear if other current FEs users have experienced anything similar.
If your library is still mainly CD based, and you want to give this a try, there are several free and low cost programs that make bit perfect conversion files from those CDs to feed the DAC. The upgrade BOM Dario created for the Mini2496 DAC is a very inexpensive and high quality solution for anyone who has yet to enter the digital domain.
P.S. - Though I've mentioned much of this before, I think I'll post part of this as others may be trying to decide whether to pre or not to pre.
To expand on Bob's comments, I went from a good but decade old CD player to ripping music to an external hard drive and then playing it over wireless to my Squeezebox and was amazed how much better the music sounded than from the CD player. I have to assume it was the better DAC (originally the Squeezebox DAC, then a Yulong D18). I have a new Shigaclone transport on the back burner, but I am curious if it will sound as good through the same DAC.
Bob,
Can you tell a difference between the sound quality using a pot for volume control or the program's digital volume control? I have tried it both ways and they are close, but my impression is that the pot may sound a little sweeter. What do you think?
Jac
I agree Jac. I tried pure digital over optical, digital over copper (RCA), analog over copper - and settled on digital over copper via BNC coax. To my ears, that's the closest I found to the warmth of a bare pot as you suggest.
Remember though, there is a sixteen foot distance between the computer and the DAC in my current setup. At one time I did try a standard 30" optical interconnect but still felt it was a little dry - though the top end was stellar. There theoretically shouldn't be any difference as digital ones and zeros are ones and zeros. I can only attribute the warmer sound to the possibility the optical is "scrubbed" more - either by the computer or the DAC input.
I'm looking forward to eliminating the JRiver and computer influences and listening to the bare pot when I get this version built.
Remember though, there is a sixteen foot distance between the computer and the DAC in my current setup. At one time I did try a standard 30" optical interconnect but still felt it was a little dry - though the top end was stellar. There theoretically shouldn't be any difference as digital ones and zeros are ones and zeros. I can only attribute the warmer sound to the possibility the optical is "scrubbed" more - either by the computer or the DAC input.
I'm looking forward to eliminating the JRiver and computer influences and listening to the bare pot when I get this version built.
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Change in Audyn True Copper
I've at hand a pair of recent production Audyn True Copper (1uF) and they're way bigger
So they must be mounted outboard now.
I'm thinking to update boards to allow slightly bigger caps like Audyn Cap Plus or Clarity Cap MR 400V and to add a bigger pad for ground input in case of outboard caps:
I've at hand a pair of recent production Audyn True Copper (1uF) and they're way bigger
So they must be mounted outboard now.
I'm thinking to update boards to allow slightly bigger caps like Audyn Cap Plus or Clarity Cap MR 400V and to add a bigger pad for ground input in case of outboard caps:
I would like to know if they have changed size of 1,2 uF caps also. Have placed an order a few days ago but did not received the caps yet.
Anyway it is appreciated if you would update board layout to be more flexible in usage of different types of caps.
1543
BTW, I've settled on feeding the FEs with a computer through a Mini2496 DAC using JRiver Media Center playing flac (S/PDIF over a BNC cable)and other non-compressed formats. For now there is no pre and I adjust the volume from within the program. If/when I bypass the audio driver in the computer I suspect a bare pot will be all that's needed. I swear the SPL of the FEs has increased significantly with continued use. I've read that transformers can improve by responding/reforming to the internal magnetic fields and that may be the cause. It would be interesting to hear if other current FEs users have experienced anything similar.
If your library is still mainly CD based, and you want to give this a try, there are several free and low cost programs that make bit perfect conversion files from those CDs to feed the DAC. The upgrade BOM Dario created for the Mini2496 DAC is a very inexpensive and high quality solution for anyone who has yet to enter the digital domain.
P.S. - Though I've mentioned much of this before, I think I'll post part of this as others may be trying to decide whether to pre or not to pre.
Hi
I am not yet a FE user, but I have signed up for the second GB.
I just wanted to comment on the digital source comments:
To my ears, s/pdif is seriously flawed if you do not use a very good FIFO solution.
Squeeze box is better, but the DAC inside is so-so.
A better soultion would be USB to I2S or finding the I2S inside the SQ box and feed this I2S to the DAC. To my ears the best DAC solution is a NOS (non oversampling ) using the TDA1541a chip. I have not yet heard the Sabre DAC and this could be a contender too, but to my ears ALL noise shaping DAC´s (1-bit and derivations of that) iare not good enough. PCM1702 , PCM56, AD1865, TDA1543, TDA1545 (EIAJ not I2S) are all good multibit DAC´s and well suited for NOS use.
Well digital are ones and zeros AND timing! Think jitter...
Just my 0.2 cents.
Koldby
I think this reflects the fact that Audyn caps are used mostly in speaker crossovers where there are fewer space restrictions. I made some of the pigtails Tom talked about but haven't installed them yet.
.....To my ears, s/pdif is seriously flawed if you do not use a very good FIFO solution.
Squeeze box is better, but the DAC inside is so-so.
A better soultion would be USB to I2S..... PCM1702 , PCM56, AD1865, TDA1543, TDA1545 (EIAJ not I2S) are all good multibit DAC´s and well suited for NOS use.
Well digital are ones and zeros AND timing! Think jitter...
Good point on the jitter. I too am waiting for a Sabre 32 based DAC and have some other I2s solutions to try. However, for this thread, I think it's only necessary to point out the availability of the digital format as an alternative to analog/CD as a source for new FE builders in their initial auditioning setups.
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I got mine yesterday and was in fact wondering how would i fit them... any possible problem due to the length of the leads?
Anyhow this allows me to use the unenameled part of the lead, avoiding the use of the solder pot
The TC in pic came from Audiophonics too.
Just did some listening tests.
I would say the new ones have similar detail but I would say a somewhat different timbre, now passing the Isotek... let's hear after.
Tried the Audyn Cap Plus too, they're better than Vishay V-735 (the industrial cap in BOM), maybe, and cost less.
Not as goos as the TC, obvioulsy.
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Dario,
Can you give the length and diameter of the new TCs?
Also, regarding the board modification, I'm not sure I understand how you were imagining use of the new signal ground. Can you explain a bit more, please?
I've been thinking about a comment Andrew made recently. To paraphrase, the inductance loop between the signal and the return path needs to be as small a loop area as possible for the best high frequency sound. If you are using a bypass cap (as I am), it is the high frequency path and should be as close to the return path (ground plane, for example) as possible. If only one cap is used (Audyn TC and most others), then the cap and the return path should still have the smallest loop area possible. I think that is what you are trying to do for an off-board cap mounting, but I am not clear.
Jac
Can you give the length and diameter of the new TCs?
Also, regarding the board modification, I'm not sure I understand how you were imagining use of the new signal ground. Can you explain a bit more, please?
I've been thinking about a comment Andrew made recently. To paraphrase, the inductance loop between the signal and the return path needs to be as small a loop area as possible for the best high frequency sound. If you are using a bypass cap (as I am), it is the high frequency path and should be as close to the return path (ground plane, for example) as possible. If only one cap is used (Audyn TC and most others), then the cap and the return path should still have the smallest loop area possible. I think that is what you are trying to do for an off-board cap mounting, but I am not clear.
Jac
5cm x 4cm (old ones where 3.6cm x 2.6cm).
I suspect they're the old ones incapsulated in a tube filled with resin, maybe for better damping or whatever...
Simply it gives an alternate way of mounting offboard caps.
The original planned way was to connect the cap to RCA hot and then using a traditional wire with molex plug to the molex connector on board (C13 position shorted on board).
With the new signal ground (yet to be finalized, in this moment it's only an idea) pad it's possible to connet the cap directly to the PCB (no need to short C13 position) mantaining a small loop with the hot side of signal.
But as I'm writing it I'm thinking to leave it out, I still prefer the original way of connecting an outboard cap...
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The new TC seem to have a slighlty different timbre, they sound really great but a bit more open (or less full if you want).
They're pretty fine.
Less refined and full than TC (old and new), though.
Sure. As usal the effect was not irrelevant...
Phew! I'm lucky I like them, then...
They're pretty fine.
Less refined and full than TC (old and new), though.
Sure. As usal the effect was not irrelevant...
If you don't like them as much as I do, I'm kicking you out of the club.
Phew! I'm lucky I like them, then...
Dario,
Thanks for the measurements. Those things are big!
Now that I understand what you have in mind for the new signal ground, I like it. I had thought of doing something similar on an RC board using the ground end of the R10 connection that has been removed in the newer boards. I would encourage you to include the new signal ground because it is easy and doesn't negatively affect anything. The only suggestion would be to rotate the new signal ground away from the direct return line of a traditional C13 mounted on the board.
Alas, I have already purchased enough boards to cover all the projects I can think of at this point, so I'll have to work out my best solution on the existing boards.
Jac
Dario, on the topic of offboard caps and Andrews comments. Right now my input ground is mounted at the standard location (the molex connector pad) but my input hot is connected at the furthest point from the ground and no jumper was used. What effect could this distance have? Do you think it is worth experimenting with a jumper?
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