These days I tend to use what I have lying around for a project like the regulated PSU for my IGC! To say that I had hand-picked the components would be nothing but BS!
However, the components that I do have lying around were originally bought with some sort of preference so to answer your question:
Resevoir caps 10,000 DNM slit foils
LM338 input pin bypass caps - 4.7uF polyester (chosen for their size as these were added after the circuit was built on the advice of NealG)
LM338 output pin bypass caps - 0.33uF polypropylene.
Caps on LM3875 100 uF Panasonic FC's because I like them! I will be trying lower values here though.
Resistors - metal film.
Protection diodes - IN4002
Rectifier diodes - MUR860
Basically, whenever I can, I like to use polypropylene caps or polystyrene for very small values. If size is an issue I may go for polycarbonate or polyester.
I can't answer the second part of your question, as I have not yet built any of my GC's with 'standard' components and then upgraded them. There are so few parts in a GC, it seems a bit of a pointless exercise not to build it as you want in the first place! 😉
I'm sitting here laughing...
Because some people think that an amp that sounds good with difficult speakers can't sound good with "easy" speakers.
I'm laughing too because you guys think I only have one pair of speakers, and worse than that, that I only test this on my systems.
This thread was opened on June 25, 2003:
http://www.diyaudio.com/forums/showthread.php?s=&threadid=16928
From the begining that I say that it's very beneficial to have a good pre.
Ultra-minimalists (PD included) doubted.
No problem.
I have other GCs, integrated amps, and from that moment I started testing buffers.
They always brought improvements.
Recently, PD admited that a good pre improves the sound of the GC.
Then... what's an op-amp used as a buffer between a volume pot and a chip amp other than a pre with a gain of 1?
And his pre is based on two op-amps.
And the OPA2604 is much inferior than the OPA627.
No matter the implementation of "his" copied pre, do you want better than a buffer?
The op-amp used as a buffer is needed on the inverting topology, even if you have a good pre.
If not, don't bother to use a pre, make an integrated amp.
And this implementation is what sounds best to ME.
I know how to kill the sound of these op-amps.
I don't trust Peter to implement them.
And the sound that he describes from his copy of "my" amp tells me exactly that his problem is on the OPA627.
This is all too silly, you guys go on if you will, do it if you want, I don't bother.
Moderators, If you want, delete all this thread.
I'm sorry for sharing my experiences.
It's my last time.
Thanks for your time!
😎
Because some people think that an amp that sounds good with difficult speakers can't sound good with "easy" speakers.
I'm laughing too because you guys think I only have one pair of speakers, and worse than that, that I only test this on my systems.
This thread was opened on June 25, 2003:
http://www.diyaudio.com/forums/showthread.php?s=&threadid=16928
From the begining that I say that it's very beneficial to have a good pre.
Ultra-minimalists (PD included) doubted.
No problem.
I have other GCs, integrated amps, and from that moment I started testing buffers.
They always brought improvements.
Recently, PD admited that a good pre improves the sound of the GC.
Then... what's an op-amp used as a buffer between a volume pot and a chip amp other than a pre with a gain of 1?
And his pre is based on two op-amps.
And the OPA2604 is much inferior than the OPA627.
No matter the implementation of "his" copied pre, do you want better than a buffer?
The op-amp used as a buffer is needed on the inverting topology, even if you have a good pre.
If not, don't bother to use a pre, make an integrated amp.
And this implementation is what sounds best to ME.
I know how to kill the sound of these op-amps.
I don't trust Peter to implement them.
And the sound that he describes from his copy of "my" amp tells me exactly that his problem is on the OPA627.
This is all too silly, you guys go on if you will, do it if you want, I don't bother.
Moderators, If you want, delete all this thread.
I'm sorry for sharing my experiences.
It's my last time.
Thanks for your time!
😎
Re: I'm sitting here laughing...
I quote myself:
I will say that the regulated design will be more stable into difficult loads and it will drive power hungry speakers better. For these two reasons I think more people will get better performance from an amp. with a regulated power supply. I exclude battery powered designs because almost no one will build and live with one of these long term.
Carlosfm please read slowly and carefully before going off. No where did I say "Because some people think that an amp that sounds good with difficult speakers can't sound good with "easy" speakers." What I said is above. That is a big difference from what you read into it.
Ok, you used other systems to test with as well Great! I'll still bet that they were much like yours in quality and components and that's OK. You did still use One common part of the system every time, your ears and you preferences.
I think your version of the National based amp may be a very good amp., maybe the best of the type, I don't know because I haven't listened to yours, on every speaker, with every preamp and with every source. You haven't either.
Later BZ
carlosfm said:
I quote myself:
I will say that the regulated design will be more stable into difficult loads and it will drive power hungry speakers better. For these two reasons I think more people will get better performance from an amp. with a regulated power supply. I exclude battery powered designs because almost no one will build and live with one of these long term.
Carlosfm please read slowly and carefully before going off. No where did I say "Because some people think that an amp that sounds good with difficult speakers can't sound good with "easy" speakers." What I said is above. That is a big difference from what you read into it.
Ok, you used other systems to test with as well Great! I'll still bet that they were much like yours in quality and components and that's OK. You did still use One common part of the system every time, your ears and you preferences.
I think your version of the National based amp may be a very good amp., maybe the best of the type, I don't know because I haven't listened to yours, on every speaker, with every preamp and with every source. You haven't either.
Later BZ
Re: What is high-end?
Repeating myself again, I don't use the LM3875 for a loooong time.
Anyway, a note for you:
Please read the complete title of my thread, not just the word "high-end".
Get it?😉
I said (joking) that this seams more like a Krell than a GC.
Did I say this is better or even similar to a Krell?😱
Anyway, Jeff Rowland uses the LM3886, I think you may call those amps cheap hi-fi.
I was not refering to your post.
Other people said it on this thread.
There are three variables here:
1. Regulated PSU
2. Input buffer
3. Inverted topology
You may test all these and take your conclusions, if you dare.
peranders said:
Repeating myself again, I don't use the LM3875 for a loooong time.
Anyway, a note for you:
Please read the complete title of my thread, not just the word "high-end".
Get it?😉
I said (joking) that this seams more like a Krell than a GC.
Did I say this is better or even similar to a Krell?😱
Anyway, Jeff Rowland uses the LM3886, I think you may call those amps cheap hi-fi.
HDTVman said:
I was not refering to your post.
Other people said it on this thread.
There are three variables here:
1. Regulated PSU
2. Input buffer
3. Inverted topology
You may test all these and take your conclusions, if you dare.
Hi Nuuk, I used .47uF there!
My setup is NI, no buffer, 3875, regulated supplies, 300VA 2x25V, BHC 10,000uF res caps.
Other ‘titbits’ for to try: Adjust the 338 bypass to suite you, don’t take it that .047uF is ‘right’, this cap changes the sound quite a bit.
I also like the FC caps but settled on 100uF standard Blackgates, I have not tried anything lower in value as I struck the balance I was after.
Let it run and run, the GC seems to get better and better if you leave it powered up 24x7.
When Carlos says use an active pre I would agree. The GC sounds better to my ears with one. I suspect part of this is down to a low o/p impedance. I use a valve Cathode Follower pre, unity gain, nothing special but it adds ‘body’ to the sound for me.
Yes, IMHO, I suspect a lot of the minimal GC out there suffer from LF stability, a regulator generally will kill such problems but it may also introduce others hence the need for bypassing the input and output. I had issues until I bypassed the 338 correctly. My GC now drives 35 into 4 Ohm at 50HZ, it would never do that before.
Before you go Carlos, commiseration about the football but many thanks for the ‘spark’ to go and try a regulated PSU.
Hey!
I only said this is the last thread I open here.
It isn't worth the trouble.
I didn't say I'll go away.
I don't know if I was clear...
Anyway, I would like this thread to be deleted, because I seam to have anoyed too many people.
It was all ok until commercial interests came into play, but anyway, please do that, moderators.
Thanks.
Note: PD is asking questions about op-amps on my other thread.
Why?😕
😀
I only said this is the last thread I open here.
It isn't worth the trouble.
I didn't say I'll go away.
I don't know if I was clear...
Anyway, I would like this thread to be deleted, because I seam to have anoyed too many people.
It was all ok until commercial interests came into play, but anyway, please do that, moderators.
Thanks.
Note: PD is asking questions about op-amps on my other thread.
Why?😕
😀
There a lot of people here, including myself, that would be greatly disappointed if you leave. Don't let this argument get to you this way.
There is much valuable information on this thread now. Much of it is contributed by people other than Carlos, so he can't just say "delete the thread!" Others have work to make clear schematics from his descriptions.
Many of the comments are about Carlo's circuits, so it would be unfair to remove his posts, leaving the comments of others without context, and the time spent by all getting a clear idea of what Carlos is talking about. Just starting the thread doesn't mean that you "own" it. Once you have written to the forum, you can't necesarily retract your words. They are now part of the forum
Perhaps the threads can be "cleaned up" but perhaps the posters should keep in mind that their words will stay long after they are upset, making them look quite foolish. Perhaps your children will be reading these posts someday! I note Carlos is still complaining about Peter- he just can't stop apparently 🙄
Feel free to delete any of my posts as they seldom were directly regarding the circuits. Some of the responses to my posts are quite useful and must stay.
Many of the comments are about Carlo's circuits, so it would be unfair to remove his posts, leaving the comments of others without context, and the time spent by all getting a clear idea of what Carlos is talking about. Just starting the thread doesn't mean that you "own" it. Once you have written to the forum, you can't necesarily retract your words. They are now part of the forum
Perhaps the threads can be "cleaned up" but perhaps the posters should keep in mind that their words will stay long after they are upset, making them look quite foolish. Perhaps your children will be reading these posts someday! I note Carlos is still complaining about Peter- he just can't stop apparently 🙄
Feel free to delete any of my posts as they seldom were directly regarding the circuits. Some of the responses to my posts are quite useful and must stay.
Variac said:
I made the tests, I described the components I used, and I posted the schematics.
I am very thankful for a member here who made the schematics very nice and clean, based on my recommendations.
Variac said:
He can open his threads and ask whatever he likes, I won't even go there, he doesn't need to post on my threads.
After what he done to this thread, he's not welcome.
I'm sorry, I hope you understand.
I've had enough.
Peace.
carlosfm said:
Sorry Carlos, I didn't know I was not welcome.
Moderators, please remove my post in Carlos' other thread. I'll do my best not to post there anymore.
Peace.
I am not sufficiently thick-skinned not to try it (regulating the HV rails), just skeptical. I would not want to see Carlos or his thread disappear. Perhaps this despondency is due to a modest bout of depression felt both in Lisbon and here in NJ (as Newark NJ is the 2nd capital of Port) with the recent football results.
-- right now I am working on an amplifier power supply "test-bed" -- using one of my 2-Horsepower Trygon's -- so eventually, within the next couple weeks, we'll get to deliver some empirical results.
-- right now I am working on an amplifier power supply "test-bed" -- using one of my 2-Horsepower Trygon's -- so eventually, within the next couple weeks, we'll get to deliver some empirical results.
jackinnj said:
What are you talking about?😕
What a confusion!😕
Football here?😕
Check my post on off-topic.
I don't live for football.
Congratulations Greece!
You won't see me complaining about the ref.
BTW, just for your information (this is nonsense...) the second portuguese "capital" is Paris.
I don't know where you're trying to get, anyway...
Peter is Canadian...
But does it matter?
Oh please, delete the thread.
I started it, I should have the right to.
But it's not you that can make me disappear.
Anyway, all, for your information, I don't take back anything I said, and no, my son won't feel sorry for me if he reads this someday.
I will defend myself whatever you do.
Delete what you want, for me that's ok.
If you criticize with a sense, I'll take it, no problems at all, as always.
There are some members here from who I can learn some things, and that's very nice.
Others are just a headache, so convinced in "Mr. I know it all", perfect amps, perfect layouts...
What some people have done here was to come, send one, and go.
Beautiful.
Some valuable members have gone away, others come here much less often.
This is going well, well done.
This forum could be much better, and I'd like it to be.
I have a feeling, anyway, that this was not in vain.
People who tried this liked it.
I'm glad they did.
I'm closing this thread, as seems to have ceased to be useful. it will be "weeded" in the near future of off-topic posts.The topic is interesting, and hopefully will reappear in future well tempered threads.
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