Tested my mini/a30 using direct output from the analog out of a compter CDP. Plays and sounds good but no real volume on either on the mini side or the a30 side.
No problem. Took it upstairs to the real stuff and connected it a preamp to get a little more gain.
Didn't play. Nothing on the Mini side or on the 30 side.
I fussed a little and it played for a couple seconds after a power cycle then went quiet. Then I noticed that it smoked a little RC circuit I placed on the GND connector of the PS boards. The RC thing was to put a brick on any loops, a' la Nuuk's GC site.
Back down stairs, clipped out the cooked RC... it was the R that burned and connected GND directly. Hooked back up to the comp CDP and everything was fine. Played, but not very loud. All channels fine. The 30 watt A30 channels only very slightly louder than the 10 watt Mini channels?????
I broke out the MOX active cross that I built and connected to the "buffer out". From recollection, this is just a tiny amount of gain. Plays louder but the 30 side still isn't much louder than the Mini side.
Anybody know what may be going on? Any ideas or should I go back to the "pre"?
No problem. Took it upstairs to the real stuff and connected it a preamp to get a little more gain.
Didn't play. Nothing on the Mini side or on the 30 side.
I fussed a little and it played for a couple seconds after a power cycle then went quiet. Then I noticed that it smoked a little RC circuit I placed on the GND connector of the PS boards. The RC thing was to put a brick on any loops, a' la Nuuk's GC site.
Back down stairs, clipped out the cooked RC... it was the R that burned and connected GND directly. Hooked back up to the comp CDP and everything was fine. Played, but not very loud. All channels fine. The 30 watt A30 channels only very slightly louder than the 10 watt Mini channels?????
I broke out the MOX active cross that I built and connected to the "buffer out". From recollection, this is just a tiny amount of gain. Plays louder but the 30 side still isn't much louder than the Mini side.
Anybody know what may be going on? Any ideas or should I go back to the "pre"?
Yes, these are cookbooked from the Brian GT chipamp.com/aleph site.
Negative reaction??? ... are those the source resistors?
http://www.diyamps.com/aleph/docs/miniAleph-sch.pdf
Negative reaction??? ... are those the source resistors?
http://www.diyamps.com/aleph/docs/miniAleph-sch.pdf
I don't know the exact numbers but the Aleph amps in general, being only 2 gain stages, have considerably less gain than a 'regular' amp. Therefore they require more "drive" than a 'regular' amp to approach the same output. I'm thinking you may not be giving either enough input and you haven't even reached the mini's potential ....maybe?
I'm guessing here
: Aleph ~ 26dB gain <<>>Regular amp 30dB gain
I'm guessing here
: Aleph ~ 26dB gain <<>>Regular amp 30dB gainI'm not the only one...
http://www.diyaudio.com/forums/showthread.php?s=&postid=5373&highlight=#post5373
So maybe it's right.
I would still like to know what cooked that GND RC network...
DC offset from the pre?
http://www.diyaudio.com/forums/showthread.php?s=&postid=5373&highlight=#post5373
So maybe it's right.
I would still like to know what cooked that GND RC network...
DC offset from the pre?
Banned
Joined 2002
chipco3434 said:
Well the a30 has more power but do you really need it ? I have noticed 2 things when using my 4 aleph mini's.
1) When using a passive pre-amp and a nice line stage from my buffer/dac they are pretty damn loud.
2) When using a pre-amp they get even louder. Not to clarify i have 4 mini a's running at 20V rails probably ( guess ) about 15 watts x 4 to 2 tower speakers in bi-amp mode. ID have to say that these little mini a's are Freaking loud and clean.. I maxed mine out and still clean all the way up to full. Im glad i have 15 watt amps instead of 100 watt ones.
When i get my new pre-amp from Russ White i bet these will sound even cleaner and better..And even louder. I noticed that the mini a's have lots of power if you have a good pre-amp with lots of gain.
J
When the RC to ground at the output is cooked, it always
means high power ultrasonics, almost always system oscillation.
I say system because an amplifier's internal oscillation is almost
always at low power levels, but if you bleed the output of an
amp back to the input, you often see full power up around
100 KHz or so. Most often this is due to bad input grounding on
the cables. It could also be the MOX putting out power
ultrasonics.
means high power ultrasonics, almost always system oscillation.
I say system because an amplifier's internal oscillation is almost
always at low power levels, but if you bleed the output of an
amp back to the input, you often see full power up around
100 KHz or so. Most often this is due to bad input grounding on
the cables. It could also be the MOX putting out power
ultrasonics.
chipco3434 said:
forgot to write one thing:
with not so efficient spks,watt difference between various amps will be smaller,in comparison with more efficient spks used for same test;
interesting- with that more efficient spks all other differences between various amps will be easier to hear.....
some of these phenomenons are easy to explain logically,physically and electrically,but some are not so easy
for instance-if you use pair of KH, you can't find two same sounding amps;
even difference of few watts between (in all other areas similar) two amps is pretty easy to hear;
not to mention differences as dynamic potential etc and all other fifi mumbo jumbo............
Thanks Nelson... another mystery solved.
Do you mean that the RCA cables on the input could have made inadequate contact? I cooked the RC with the pre, not the MOX.
Feel free to do the Samuel Jackson thing on me...
"Do you speak English ^$@%&^$*? Do you speak English?
...but I want to be perfectly clear on this point.
Better scope it, eh?
Choky...
It is pretty easy to discern the power difference between the Mini and the 30 at this point.
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