Will,
I think it is worthy of experimentation because it makes the loop bigger. Besides, if you do the experiment, I hope to get the answer to a question I was curious about.:-D
Jac
In my intentions outboard caps should be mounted like I've explained, shorting C13 position and using molex pads for both hot and ground, this ensure small loop too.
So I think it would be interesting if you try it and report changes, if any.
In my intentions outboard caps should be mounted like I've explained, shorting C13 position and using molex pads for both hot and ground, this ensure small loop too.
So I think it would be interesting if you try it and report changes, if any.
Will do, I will try to get to it today, but I have a project deadline that is looming so it may be this week.
P.s. I also built a Bob inspired volume control from leftovers that sounds great!
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Hi Bob,
Thanks for the warm welcome... I just completed the Audio Sector's LM3875 Gainclone not that long ago and I'm quite happy with the sound..
I'm really looking forward to build a better amplifer like My_Ref ...
Thanks for the warm welcome... I just completed the Audio Sector's LM3875 Gainclone not that long ago and I'm quite happy with the sound..
I'm really looking forward to build a better amplifer like My_Ref ...
Welcome BTW.
I'm no expert, but on one level, the the MyRef FE should be a good match. With high impedance speakers, you need to put out higher voltages. With a gain of 30, the MyRef series should to very well with your speakers. Do you happen to know what is the gain of the Audio Sector amps you built? I assume from your comments that they play your speakers well.
Jac
Mmnnn! Leftovers! Tasty!
I think I'll go make lunch.
Seriously, your volume control looks neat and effective. What more could anyone want.
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I'm not sure of the gain of the Audio Sector Gainclone but they work very well with my spks.. Btw I'm using a diy tube preamp , so I guess that helps quite a bit as well....
Fine.
It's a TKD 2CP-601, isn't it?
From what I've read it should be way better than Alps Blue Velvet.
I finally got a chance to break away and do some soldering last night. I connected the input next to the in ground and installed a jumper on board at c13. With source connected the and no pgnd I still have hum. With inputs shorted I have no hum in the right channel but a very small amount in the left. The left channel is the one that has the input pair that is close to the k71 on both sides. With pgnd connected though I get silence no hum or hiss in both channels. I am really begining to suspect the k71s and their location. I have thought about insulating the body of the caps because they are metal to see of that helps with noise, but really at this point I think I need to rewire. I know Dario has fit these caps on the board in one of his builds so I may pull everything apart and make those and a few other changes. I should be able to do that this weekend.
Apart from hum levels, did the "small loop/C13 jumper" configuration sound different? It has been strongly suggested but not yet demonstrated that a smaller loop will yield perceptibly improved high frequency response. I doubt it will matter at all, but I am prepared to accept experimental results. I have used the C13 direct-to-board configuration (connected at the circuit side, not the input side of the C13 pads) for every MyRef build, yielding outstanding results with a moderately large loop. I think more solder joints and additional connectors, no matter how good, are more detrimental to sonics than a slightly larger loop.
It will be difficult to eliminate hum until you get input signal wiring away from power supply. Always strive to keep signal and mains as far apart as possible. Shielding or twisting wires is not as effective as physical space. This may be difficult with your current layout.
Pic is my first crude build, couple years ago. Still works perfectly, with no hum or noise. Note the input cap connects RCA directly to circuit side of C13pads. Input ground wire is completely separated.
Peace,
Tom E
It will be difficult to eliminate hum until you get input signal wiring away from power supply. Always strive to keep signal and mains as far apart as possible. Shielding or twisting wires is not as effective as physical space. This may be difficult with your current layout.
Pic is my first crude build, couple years ago. Still works perfectly, with no hum or noise. Note the input cap connects RCA directly to circuit side of C13pads. Input ground wire is completely separated.
Peace,
Tom E
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Will,
Like Tom, I am interested in hearing your thoughts on if there is a sound difference. It is a really interesting question you are playing with.
Tom,
Just curious, in the picture, how did you support the input cap in that build and how would you do it differently if you were mounting an off-board cap today? I see the cable tie, but can't see what is underneath.
Jac
Like Tom, I am interested in hearing your thoughts on if there is a sound difference. It is a really interesting question you are playing with.
Tom,
Just curious, in the picture, how did you support the input cap in that build and how would you do it differently if you were mounting an off-board cap today? I see the cable tie, but can't see what is underneath.
Jac
Surprised you could glean that much information from my crummy photography. The cap rests on (is almost encapsulated by) a thin piece of firm foam rubber which is, indeed, secured by a cable tie routed through two holes drilled in the floor of the enclosure. I still do it the same way, except now I use dense cotton soundproofing material (leftovers from lining my speaker enclosures) instead of foam to form the cap cradle. The black stuff inside the enclosure is Soundcoat damping material from Parts Connexion which is very effective on thin gauge (cheap) aluminum.
As you can see, I am not the least bit interested in attractiveness or even tidiness, but there is planning toward a goal: shorten signal paths and reduce vibration. No one will ever hear how pretty or ugly the insides of an amplifier are.
Peace,
Tom E
As you can see, I am not the least bit interested in attractiveness or even tidiness, but there is planning toward a goal: shorten signal paths and reduce vibration. No one will ever hear how pretty or ugly the insides of an amplifier are.
Peace,
Tom E
Tom and Jac, interesting question about the difference in sound. I dont know if I am looking for a difference because the question was asked, or if it is really there, but here it is.....
I did not do much listening last night after I made the changes. I checked for hum hiss etc. reconnected pgnd listened for a few minutes and went on to somthing else. It sounded good, but I did not do any critical listening. Today I listened to a few of the usual subjects through the ESS monitors. As usual the sound is amazingly clear, perfect seperation, and great soundstage. The one thing that stood out tonight, while listening to Miles Davis, kind of blue, was the soundstage. Everything seemed the same, but the soundstage seemed different. Real or imagined the soundstage seemed to come from in between the speakers and beside them more than usual. More listening will tell the tale.
As for the wiring I noticed somthing about Toms build and some of the pictures Dario has sent me. Both builds utilize short wire runs, but niether build uses twisted pairs. In Toms build the cap is the signal hot, and the signal ground is not run parallel to the cap. Not quite a right angle, but probably close enough. Now in Darios build with the K71s the caps are on the board, but the signal ground is very close to the cap, but it does not run parallel to the cap like in my build. the ground intersects the cap at a right angle. The wire runs in my build are different for both channels but similar in some areas. The ground portion that runs in between each channel is the one place they are the same.
I would of course like to keep the caps where they are, but yes Tom the sound trumps all asthetics. I think before I abandon the current mounting system I will do some expiriments with the wiring. I will shorten the paths as much as possible, I am going to split the signal hot and the signal ground at the rca at a right angle. I will report any changes. Hopefully my mistakes and subsiquent attempts to repair these errors will be of use for future builders. Sorry if this comes off as a rambling, it has been a long week!
I did not do much listening last night after I made the changes. I checked for hum hiss etc. reconnected pgnd listened for a few minutes and went on to somthing else. It sounded good, but I did not do any critical listening. Today I listened to a few of the usual subjects through the ESS monitors. As usual the sound is amazingly clear, perfect seperation, and great soundstage. The one thing that stood out tonight, while listening to Miles Davis, kind of blue, was the soundstage. Everything seemed the same, but the soundstage seemed different. Real or imagined the soundstage seemed to come from in between the speakers and beside them more than usual. More listening will tell the tale.
As for the wiring I noticed somthing about Toms build and some of the pictures Dario has sent me. Both builds utilize short wire runs, but niether build uses twisted pairs. In Toms build the cap is the signal hot, and the signal ground is not run parallel to the cap. Not quite a right angle, but probably close enough. Now in Darios build with the K71s the caps are on the board, but the signal ground is very close to the cap, but it does not run parallel to the cap like in my build. the ground intersects the cap at a right angle. The wire runs in my build are different for both channels but similar in some areas. The ground portion that runs in between each channel is the one place they are the same.
I would of course like to keep the caps where they are, but yes Tom the sound trumps all asthetics
. I think before I abandon the current mounting system I will do some expiriments with the wiring. I will shorten the paths as much as possible, I am going to split the signal hot and the signal ground at the rca at a right angle. I will report any changes. Hopefully my mistakes and subsiquent attempts to repair these errors will be of use for future builders. Sorry if this comes off as a rambling, it has been a long week!