Re: Now let it burn a few days...
Don't worry, everything is under control. I don' want to shorten wires from the transformer now.
All electronic components need some time to settle down. I think that big caps need at least few days to burn in and chip like lm3875 probably weeks.
jleaman said:Maybe shorten these wires too just to prevent disaster and problems.
Don't worry, everything is under control. I don' want to shorten wires from the transformer now.
Upupa Epops said:Why ? Amp is goat cheese or wine ?
All electronic components need some time to settle down. I think that big caps need at least few days to burn in and chip like lm3875 probably weeks.
Member
Joined 2002
Re: Re: Now let it burn a few days...
I didn't say shorten the wires i mean shorten the exposed copper that will cause a short if crossed. Possibly short that nice transformers you have.
sinski said:
Don't worry, everything is under control. I don' want to shorten wires from the transformer now.
All electronic components need some time to settle down. I think that big caps need at least few days to burn in and chip like lm3875 probably weeks.
I didn't say shorten the wires i mean shorten the exposed copper that will cause a short if crossed. Possibly short that nice transformers you have.
On this picture You can see that the space beetwen wires:
http://s7.photobucket.com/albums/y252/praganj/?action=view¤t=IMG_3593.jpg
This is not a ready amp, this is just experimental setup. Anyway thank you for the hint.
http://s7.photobucket.com/albums/y252/praganj/?action=view¤t=IMG_3593.jpg
This is not a ready amp, this is just experimental setup. Anyway thank you for the hint.
Upupa Epops said:Probably week ? Your ears maybe.... it is about psychoacoustic...
I tend to agree.
I have just added 2 new LM3875 modules to my amp. The originals are 2 years old. They were all purchased at the same time and are identical using identical components.
I have been swapping between these "old" and "new" amps and didn't noticed any obvious differences. If there were any differences they must have been very minor or the burn in period was very quick and I missed the differences.
I was not testing specifically for "old" and "new" just experimenting with parallelling and bi-amping, so there is a chance that with my random testing procedures I missed something.
regards
XELB said:Are your trafo cables protected with enamel ?
Hi XELB,
If you look closely at the picture you can see the enamel has been stripped to 1 or 2 mm before the insulation. With the toriods I buy, this seems to be "standard" practice.
regards
Burn -in
Yes, burning in seems to happen very quickly. I noticed on my first LM3875 that it was a mattter of a couple of minutes, not weeks of playing 12-24 hrs a day. But we could go into a whole new thread on this topic alone.......(burning in speaker wires and their direction of electron flow and god knows what else)......
Brett.
Yes, burning in seems to happen very quickly. I noticed on my first LM3875 that it was a mattter of a couple of minutes, not weeks of playing 12-24 hrs a day. But we could go into a whole new thread on this topic alone.......(burning in speaker wires and their direction of electron flow and god knows what else)......
Brett.
Re: Power supply
Hi Brett,
Yes, that's the amp. It changes a lot, lucky I made it easy to reconfigure.
Here's a current picture. The top 2 amps are the originals and the bottom 2 are the new ones. PSU is shared.
regards
enzedone said:Greg; On your second amp did you use the same power supply set-up? I think i saw some picks of one of your LM3875's a while back. Was it from Brians site? Is your new one similar to that?
Hi Brett,
Yes, that's the amp. It changes a lot, lucky I made it easy to reconfigure.
Here's a current picture. The top 2 amps are the originals and the bottom 2 are the new ones. PSU is shared.
regards
Attachments
Hi,
There was a small break in my gc experiments. In last days i visited few friends with different setups and this is my final opinion:
1. When my gc is connected to a very good living and rocking preamp like naim nac 72/hicap then the music is living and rocking
2. Passive amp is working sometimes better, sometimes worse, but only with a very good preamp there is a real good prat.
3. In a passive mode the snubber ps seems to work better, but snubber IMHO is like kind of "loudness" switch. There is little more bass and punch, but the sound is more tensed and not so natural and i cannot listen so long to he music as with original Premium Kit design.
4. I switched back to original "no snubber" design with 2x1500uF very close to LM3875 and for my taste the sound is more natural, the sound is flowing more naturally and finally i prefer it over the "snubber" version. Sorry Carlos
So now i need a really good rocking preamp. Any suggestions ?
There was a small break in my gc experiments. In last days i visited few friends with different setups and this is my final opinion:
1. When my gc is connected to a very good living and rocking preamp like naim nac 72/hicap then the music is living and rocking
2. Passive amp is working sometimes better, sometimes worse, but only with a very good preamp there is a real good prat.
3. In a passive mode the snubber ps seems to work better, but snubber IMHO is like kind of "loudness" switch. There is little more bass and punch, but the sound is more tensed and not so natural and i cannot listen so long to he music as with original Premium Kit design.
4. I switched back to original "no snubber" design with 2x1500uF very close to LM3875 and for my taste the sound is more natural, the sound is flowing more naturally and finally i prefer it over the "snubber" version. Sorry Carlos
So now i need a really good rocking preamp. Any suggestions ?
I found an AD815 preamp based on the work done in this thread gave me all the PRAT i need. However never having listening to a Naim setup i could compare it. It has given me my best sounding setup by a reasonable margin, very highly recommneded.
http://www.diyaudio.com/forums/showthread.php?s=&threadid=40783
Phil
http://www.diyaudio.com/forums/showthread.php?s=&threadid=40783
Phil
ModWright SWL 9.0SE is the popular choice with chip amps.
It is? I can find only one other reference to it on the whole of diyAudio (and that was by the same person)!
Together with Zu speakers (usually Druids)
http://www.audiocircle.com/circles/...tdays=0&postorder=asc&highlight=patek&start=0
http://www.audiocircle.com/circles/...tdays=0&postorder=asc&highlight=patek&start=0
Just out of interest, have you tried a shunted passive attenuator?
I have an Audiosector premium kit in dual mono config (2v 18-0-18v, 120VA, 2x rectifiers, with 1500uf on the rails). I use a 50k alps blue dual log pot, shunted with 47k metal film (0.25w) resistors. The resistor is directly in the signal path and the pot as a bypass to signal ground. This keeps the signal path as short as possible, as it no longer goes through the wiper arm of the pot. I find it really opens up the sound in terms of clarity, especially at lower volume levels.
Regards,
Chris.
I have an Audiosector premium kit in dual mono config (2v 18-0-18v, 120VA, 2x rectifiers, with 1500uf on the rails). I use a 50k alps blue dual log pot, shunted with 47k metal film (0.25w) resistors. The resistor is directly in the signal path and the pot as a bypass to signal ground. This keeps the signal path as short as possible, as it no longer goes through the wiper arm of the pot. I find it really opens up the sound in terms of clarity, especially at lower volume levels.
Regards,
Chris.
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