First of all, thanks for all your replies.
Peter,
You made me laugh, hahaha hemisphere!!! I was at work, and it was almost 40ºC and I was... well, I think I'm a bit more stupid than I thought (and the txaikoski thing was hard to beat
)
I made a Y connector to split the signal from the DVD to both GC and 1801 inputs. My GC has a 50Kpot. The output of both is relay-ed to the speakers with the same type of cable. I energize the relay and one feeds the speaker, I denergize and the other one does.
So, I'm not using the denon pre stage for the GC.
When I say check the volume I don't mean to perform the test at low and high output, I mean check that both have the same gain. A very very very small difference gives the matchball.
My chip was the TF version, insulated, does this make any difference?
Mothman,
the problem isn't which I like more, is that I'm not able to distinguish!
BTW, I like Prokofiev 2nd the most.
Peter,
You made me laugh, hahaha hemisphere!!! I was at work, and it was almost 40ºC and I was... well, I think I'm a bit more stupid than I thought (and the txaikoski thing was hard to beat
)I made a Y connector to split the signal from the DVD to both GC and 1801 inputs. My GC has a 50Kpot. The output of both is relay-ed to the speakers with the same type of cable. I energize the relay and one feeds the speaker, I denergize and the other one does.
So, I'm not using the denon pre stage for the GC.
When I say check the volume I don't mean to perform the test at low and high output, I mean check that both have the same gain. A very very very small difference gives the matchball.
My chip was the TF version, insulated, does this make any difference?
Mothman,
the problem isn't which I like more, is that I'm not able to distinguish!
BTW, I like Prokofiev 2nd the most.
Hi Raka,
I use the LM3886tf in a non-inverted circuit.I like the insulated version.I have both and the TF's are actually finished quite a bit better than the T's.
I don't have a digi-cam or I'd post some pics of my amp.
Is yours built-up in a decent case? and are you using the PSU I saw in your earlier post?
If so whats your trafo voltage and ground configuration.
I've found that these two elements have a major influence on sound,which by the way what do you hear with your ear to the speaker,input connected amp at idle of course.
Regards,
Bob
I use the LM3886tf in a non-inverted circuit.I like the insulated version.I have both and the TF's are actually finished quite a bit better than the T's.
I don't have a digi-cam or I'd post some pics of my amp.
Is yours built-up in a decent case? and are you using the PSU I saw in your earlier post?
If so whats your trafo voltage and ground configuration.
I've found that these two elements have a major influence on sound,which by the way what do you hear with your ear to the speaker,input connected amp at idle of course.
Regards,
Bob
Yes, it's built in a decent case. I salvaged a Basler AVR casually with heatsinks at both sides. It's a LM3875 inverted as the complete Thorsten. I think it's reasonably well p2p-ed with very short wires. Trafo is 18-0-18 and two bridges (MSR860) for all the amp (I simply abandon the four bridges idea). Two star grounds, one for small signal and one for power, tied together. Earth wire doesn't help a lot, and I discovered that tied directly to ground and then a 1K resistor to case was the less noisy solution.
Input pot is a standard one 50K
Pot at maximum with CD stopped, and from the chair you hear nothing. If you get very near you can hear a bit of hum and hiss, very little but is there.
Any suggestion or diagram for the grounding and earthing?
BTW, what 3886 config did you use?
And yes, the switch gear is not a way to improve the signal path, but it attacks both amps, doesn't it?
Input pot is a standard one 50K
Pot at maximum with CD stopped, and from the chair you hear nothing. If you get very near you can hear a bit of hum and hiss, very little but is there.
Any suggestion or diagram for the grounding and earthing?
BTW, what 3886 config did you use?
And yes, the switch gear is not a way to improve the signal path, but it attacks both amps, doesn't it?
Raka
The Y adapter and the fact that both amps inputs are connected to the source at the same time is seriously detrimental to the sound. Ditto the presence of a relay (unspecified type). The combined effect of the two may seriously decrease all audible differences. Have you tried listening to each amp without the switching arrangement? Do they still sound the same? Conducting an AB of decent quality is very, very difficult.
Let me relate the following 20 year old story. When i was at university and generally trying to develop a sceptical scientific mind and an ability to debunk myths (that didn't seem to work too well) i had a friend who was seriously into music listening. He had a simple, cheap system, which amazingly (possibly due to ribbon tweeters) was very perceptive to small changes. Once i brought my 3-head tape deck to his place to do some illegal copying and thought of impressing him with the minute difference between his LPs and my copy in A/B (the deck allowed for monitoring by a switch). And yes, the difference was indeed small. My buddy had a listen and said something was not right with the sound. He changed the A/B switching from within the deck to the amp. Much more perceptible difference. He was still not happy though, as he proceeded to completely disconnect the deck input when playing the Lp and syncronise the playback. Now the difference between Lp and tape was staggering. I couldn't believe that the deck input circuitry would have such an effect on the sound so we continued to investigate. At the end it turned out that the one metre length of cable connected to the tape-out on the amp (no tape buffer!) was sufficient to seriously degrade the sound of the phono stage. This is certainly not surprising but still serves to illustrate that a clean A/B is not so easy.
cheers
peter
The Y adapter and the fact that both amps inputs are connected to the source at the same time is seriously detrimental to the sound. Ditto the presence of a relay (unspecified type). The combined effect of the two may seriously decrease all audible differences. Have you tried listening to each amp without the switching arrangement? Do they still sound the same? Conducting an AB of decent quality is very, very difficult.
Let me relate the following 20 year old story. When i was at university and generally trying to develop a sceptical scientific mind and an ability to debunk myths (that didn't seem to work too well) i had a friend who was seriously into music listening. He had a simple, cheap system, which amazingly (possibly due to ribbon tweeters) was very perceptive to small changes. Once i brought my 3-head tape deck to his place to do some illegal copying and thought of impressing him with the minute difference between his LPs and my copy in A/B (the deck allowed for monitoring by a switch). And yes, the difference was indeed small. My buddy had a listen and said something was not right with the sound. He changed the A/B switching from within the deck to the amp. Much more perceptible difference. He was still not happy though, as he proceeded to completely disconnect the deck input when playing the Lp and syncronise the playback. Now the difference between Lp and tape was staggering. I couldn't believe that the deck input circuitry would have such an effect on the sound so we continued to investigate. At the end it turned out that the one metre length of cable connected to the tape-out on the amp (no tape buffer!) was sufficient to seriously degrade the sound of the phono stage. This is certainly not surprising but still serves to illustrate that a clean A/B is not so easy.
cheers
peter
Peter,
If I understood your reply completely right...
I didn't make any mistake with my spelling of Sergei, right?
Yeah, I'm aware that the setup is in any way damaging the sound, and that a proper one is not so easy. I will try to repeat the test, without the relays and the Y but checking carefully the gain of both. This point, the gain, is what I sincerely believe is perhaps fooling many of our comparisons.
I really enjoy the GC, but I think mainly because is my creation, and I'm proud of the way it plays, because I did it. As I believe you saying GC should beat my denon, I'll sell my denon and build a speaker system with higher resolution. And My Head is rumbling with biamping, biamping, all I have to do is biamping.... Stop! you'd rather fine tune the GC !! Ok, I'll buy another trafo and use the pure copper solid wire (1.4mm) I have, to make another reencarnation... yes my lord, the next one will be better than my denon. What? Panasonic caps? FC? ok, I have to buy some for my ono clone, so 4 more won't break my bank. LM1875? mmm, dunno, maybe, any input?
Please, please, could some of you make a AB for me?
If I understood your reply completely right...
I didn't make any mistake with my spelling of Sergei, right?
Yeah, I'm aware that the setup is in any way damaging the sound, and that a proper one is not so easy. I will try to repeat the test, without the relays and the Y but checking carefully the gain of both. This point, the gain, is what I sincerely believe is perhaps fooling many of our comparisons.
I really enjoy the GC, but I think mainly because is my creation, and I'm proud of the way it plays, because I did it. As I believe you saying GC should beat my denon, I'll sell my denon and build a speaker system with higher resolution. And My Head is rumbling with biamping, biamping, all I have to do is biamping.... Stop! you'd rather fine tune the GC !! Ok, I'll buy another trafo and use the pure copper solid wire (1.4mm) I have, to make another reencarnation... yes my lord, the next one will be better than my denon. What? Panasonic caps? FC? ok, I have to buy some for my ono clone, so 4 more won't break my bank. LM1875? mmm, dunno, maybe, any input?
Please, please, could some of you make a AB for me?
Hi Raka,
I used the NSC data sheets for my LM3886 without input coupling or RLC network on the output.
PSU same as yours except I wanted to optimize for the 4 ohm speakers I use so I added 2x 2200uf per side as part of the power supply then on to the chips with 2x1000uf and 100 uf bypass per supply rail.
Check out Amp Chip Diy for some good grounding info although it sounds like youv'e got it right.I connected both amps together and to the chassis and earth safety ground at the same point,no de-coupling,and my amp is dead quiet with ear to speaker.
I used the NSC data sheets for my LM3886 without input coupling or RLC network on the output.
PSU same as yours except I wanted to optimize for the 4 ohm speakers I use so I added 2x 2200uf per side as part of the power supply then on to the chips with 2x1000uf and 100 uf bypass per supply rail.
Check out Amp Chip Diy for some good grounding info although it sounds like youv'e got it right.I connected both amps together and to the chassis and earth safety ground at the same point,no de-coupling,and my amp is dead quiet with ear to speaker.
Raka,
You have a fixation on matching the levels, but that's only important on a pure A/B test.
If it's not a pure A/B test, just play with the volume at your will and see what amp do you like most.
Take that Y cable and switch out of the way and you'll see.
An A/B test is good when you have difficulty in deciding what's the best component you're testing.
I have no doubts, even withoun a pure A/B.
So, I don't see a reason to go to all that trouble.
You have a fixation on matching the levels, but that's only important on a pure A/B test.
If it's not a pure A/B test, just play with the volume at your will and see what amp do you like most.
Take that Y cable and switch out of the way and you'll see.
An A/B test is good when you have difficulty in deciding what's the best component you're testing.
I have no doubts, even withoun a pure A/B.
So, I don't see a reason to go to all that trouble.
Carlos,
Do you think you can distinguish between your GC and another amp in a AB? Are you really sure?
Why don't you AB to confirm this point? Maybe you can learn something, or maybe you start thinking. Try one without any relay, Y, or whatever, and let me know.
My fixation with the volume, is that I've discover that a slight difference in volume gives automatically a winner.
So if it's good to check a component, why is not the same good to test amps? Now I understand nothing.
Mothman,
My amp is not DEAD quiet, but quite quiet (that is enough for me).
Do you think you can distinguish between your GC and another amp in a AB? Are you really sure?
Why don't you AB to confirm this point? Maybe you can learn something, or maybe you start thinking. Try one without any relay, Y, or whatever, and let me know.
My fixation with the volume, is that I've discover that a slight difference in volume gives automatically a winner.
So if it's good to check a component, why is not the same good to test amps? Now I understand nothing.
Mothman,
My amp is not DEAD quiet, but quite quiet (that is enough for me).
Raka said:
Raka, I did many AB tests over the years, and I did them when I had difficulty in detecting a difference between two cables, two CD players, two Dacs...
It's the most effective way.
But when the difference is so clear I don't see the use, I would get the same conclusion.
Don't tell me I can't detect a difference if I make an AB test, or even a blind test!
Do you need to AB test a cheap AV amp and a Krell, just to be sure?
Believe me, as Peter Daniel said, me too, I wouldn't spend my time and money with a GC if it wasn't better than what I had.
It would go to my 4th system, in the basement.
I used to have a Harman Kardon HK-690. My gainclone was quite a bit cheaper, and it toasted the HK in all aspects (except high power in low impedance loads, 300-400 W at 1 ohm or so) !
I have owned my GC for more than a year, and the sound has changed quite dramatically during that time. Some mods were improvements, some not. My amp even has been unstable for a time. Sometimes the amp was almost unlistenable (tiring), sometimes superb and very addictive. Luckily, the amp is now again in the second category. Building a (very) good GC is not as simple as it looks!
Fedde
I have owned my GC for more than a year, and the sound has changed quite dramatically during that time. Some mods were improvements, some not. My amp even has been unstable for a time. Sometimes the amp was almost unlistenable (tiring), sometimes superb and very addictive. Luckily, the amp is now again in the second category. Building a (very) good GC is not as simple as it looks!
Fedde
A/B test
While i am new in this forum i am a senior member of another chip amp forum.
As far as A/B test i have done the test with my old marantz 2238/vrs clone and my homebrew PP 6bq5 amps.
I have the output from the modded sony dvd player going to first 1 (ex. marantz) the the second going to the GC.By first setting up the amps with a heath signal generator to the same spl i believe its a valid test.
results:the GC sounds more like a combination of a good SS (control of the signal, strong bass) and the PP tube amp (warm mids but more accurate with the GC).The LF and HF extension is better with the GC than either.Speakers are fostex fe-103 horns.
As far as vibrations being induced i spent about 5 years at Boeing aerospace in quality control and witnessed many vibration tests on completed components (electronic). Many of the tests required that the component be active and monitored during the tests.The results that i observed was that all components had a resonante frequency but that frequency was activated by vibrations from the outside , not internal.Well dampened components always had a much smoother response than un dampened and things like silicone fill always had smoother response.The greatest problem was with caps as induced vibrations always had a greater effect than other individual components and the frequency of the problem was never really a constant.
As a result of these observations i always fill my GC mono blocks with silicone and add spikes going into graphite blocks (actually sectioned up foot callous stones) to make a combo isolation/vibration path.
thanks
ron
While i am new in this forum i am a senior member of another chip amp forum.
As far as A/B test i have done the test with my old marantz 2238/vrs clone and my homebrew PP 6bq5 amps.
I have the output from the modded sony dvd player going to first 1 (ex. marantz) the the second going to the GC.By first setting up the amps with a heath signal generator to the same spl i believe its a valid test.
results:the GC sounds more like a combination of a good SS (control of the signal, strong bass) and the PP tube amp (warm mids but more accurate with the GC).The LF and HF extension is better with the GC than either.Speakers are fostex fe-103 horns.
As far as vibrations being induced i spent about 5 years at Boeing aerospace in quality control and witnessed many vibration tests on completed components (electronic). Many of the tests required that the component be active and monitored during the tests.The results that i observed was that all components had a resonante frequency but that frequency was activated by vibrations from the outside , not internal.Well dampened components always had a much smoother response than un dampened and things like silicone fill always had smoother response.The greatest problem was with caps as induced vibrations always had a greater effect than other individual components and the frequency of the problem was never really a constant.
As a result of these observations i always fill my GC mono blocks with silicone and add spikes going into graphite blocks (actually sectioned up foot callous stones) to make a combo isolation/vibration path.
thanks
ron
Re: A/B test
Hi and Welcome to our forum
This is very interesting for me. For next mono block I was planning to fill most of the spare space in a small cast aluminium box with small graded stones and then pour in polyeurathane resin to fill in the gaps between the stones.
how does this idea sound to you ?
after reading an interview with the gaincard makers I was wondering if a harder setting resin would be better as they don't seem so keen on damping.
sounds like the caps would benifit from this most.
trouble is if I don't like the sound there is no way back !!!
cheers
mike
ron clarke said:
Hi and Welcome to our forum
This is very interesting for me. For next mono block I was planning to fill most of the spare space in a small cast aluminium box with small graded stones and then pour in polyeurathane resin to fill in the gaps between the stones.
how does this idea sound to you ?
after reading an interview with the gaincard makers I was wondering if a harder setting resin would be better as they don't seem so keen on damping.
sounds like the caps would benifit from this most.
trouble is if I don't like the sound there is no way back !!!
cheers
mike
ron,
Spikes, although sometimes effective in a sonic point of view, don't isolate a device from vibrations.
To isolate from vibrations you need something soft like sorbothane.
But you need to listen to both, because this is turbulent waters and sometimes what you think that may not work is what gives the sound you like most...
Spikes, although sometimes effective in a sonic point of view, don't isolate a device from vibrations.
To isolate from vibrations you need something soft like sorbothane.
But you need to listen to both, because this is turbulent waters and sometimes what you think that may not work is what gives the sound you like most...
ron
Well to be honest the spikes were laying around and look cool LOL.I have the blocks on a flexy table and with the isolation pads (used to great effect on other components) the sound is very clear and clean and crisp.
My background is more centered around ME than EE (only did electronics when the job called for it) and as stated the tests were very controlled.Although a missle control system never had isolation spikes, the fill of the component sections was always something that was more flexible than rigid.Remember these were things that were flying thru rough air currents and had to be protected from explosions (sometimes nuclear).
ron
Well to be honest the spikes were laying around and look cool LOL.I have the blocks on a flexy table and with the isolation pads (used to great effect on other components) the sound is very clear and clean and crisp.
My background is more centered around ME than EE (only did electronics when the job called for it) and as stated the tests were very controlled.Although a missle control system never had isolation spikes, the fill of the component sections was always something that was more flexible than rigid.Remember these were things that were flying thru rough air currents and had to be protected from explosions (sometimes nuclear).
ron
Fedde,
Interesting your comments about the fickleness of your GC, (Then you have to assume that your GC is female ) Were the changes noticed with the very same recordings?
Which improvements were the good, the bad and the ugly? I'll soon report the effect of solid core pure cooper wiring, as I expect to success here.
Ron,
Welcome and thanks a lot for your comments on your ABing!!
So, you clearly distinguished between amps, didn't you? Which output impedance has your PP?
Also interesting are your boeing experiences. When you say "activated by vibrations from the outside", we are talking about not structure borne but airborne vibrations, aren't we?
I've been bypassing the cap, and I can't hear any improvement, so that means that the cap is not the weakest link in my chain yet.
BTW, any info about your horns? any web?
Mike,
If the point is to dissipate the energy, and to be reversible, what about to fill with sand? As soon as I fine tune my GC I will try this.
Trying to find out how to open the windows for my GC to shine, I changed the interconnects ala TNT UBYTE1, and the results are very good, very very good. I will try to AB again, to see if this changes something.
Yesterday, Kachaturian concerto by God. Táraritoti, Táraritoti, ufff, sooo beautiful...
Interesting your comments about the fickleness of your GC, (Then you have to assume that your GC is female
) Were the changes noticed with the very same recordings?Which improvements were the good, the bad and the ugly? I'll soon report the effect of solid core pure cooper wiring, as I expect to success here.
Ron,
Welcome and thanks a lot for your comments on your ABing!!
So, you clearly distinguished between amps, didn't you? Which output impedance has your PP?
Also interesting are your boeing experiences. When you say "activated by vibrations from the outside", we are talking about not structure borne but airborne vibrations, aren't we?
I've been bypassing the cap, and I can't hear any improvement, so that means that the cap is not the weakest link in my chain yet.
BTW, any info about your horns? any web?
Mike,
If the point is to dissipate the energy, and to be reversible, what about to fill with sand? As soon as I fine tune my GC I will try this.
Trying to find out how to open the windows for my GC to shine, I changed the interconnects ala TNT UBYTE1, and the results are very good, very very good. I will try to AB again, to see if this changes something.
Yesterday, Kachaturian concerto by God. Táraritoti, Táraritoti, ufff, sooo beautiful...
Kachaturian
Raka
I am still keeping an eye on you and your careless attitude towards composer's names. At the moment i am split between reporting you to the moderators or the armenian embassy. The 'K' is not even heard when you pronounce the name; it's just a useless artifact of the brits spelling (Khatchaturian).
peter
Raka
I am still keeping an eye on you and your careless attitude towards composer's names. At the moment i am split between reporting you to the moderators or the armenian embassy. The 'K' is not even heard when you pronounce the name; it's just a useless artifact of the brits spelling (Khatchaturian).
peter
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