Puzzle of 6 mixed up Aleph 2

[pyro2006]

Bought 3 Aleph2 kits from a diy mail order shop overseas together with my friend, so each of us get 3 monoblocks to use for the LCR front channels for our home theater.

It was built by a referred local rep. But after a few weeks it becomes clear to us that the left and right monoblocks are running at very different temperatures, and later when my speaker builders came they measured a 1 db difference between my left and right channel and in fact a 180 phase shift ... so maybe the builder mixed up the monoblocks

Unluckily the builder no longer wants to work on these amps (he probably did 10 - 15 sets of these in a row)

Puzzle : assuming our batch of six were mixed up, how can I go about figuring the matched pairs ? Can I use the operating temperature to do a first level match ? Then what ?

What worries me is the hotter ones actually put out less volume

[Zen Mod]

Originally posted by pyro2006
Bought 3 Aleph2 kits from a diy mail order shop overseas together with my friend, so each of us get 3 monoblocks to use for the LCR front channels for our home theater.

It was built by a referred local rep. But after a few weeks it becomes clear to us that the left and right monoblocks are running at very different temperatures, and later when my speaker builders came they measured a 1 db difference between my left and right channel and in fact a 180 phase shift ... so maybe the builder mixed up the monoblocks

Unluckily the builder no longer wants to work on these amps (he probably did 10 - 15 sets of these in a row)

Puzzle : assuming our batch of six were mixed up, how can I go about figuring the matched pairs ? Can I use the operating temperature to do a first level match ? Then what ?

What worries me is the hotter ones actually put out less volume

change techie (rep) .

seems that problems are multiple

[RoboMan]

They do need some adjustments but shouldn't having too much difference as you said. If correctly built and adjusted, all mono blocks should perform the same and should be working at similar temperature. For the one that is out of phase, definitely there is something wrong (may be just simply the output terminals are reversed). It seems that your Aleph2s are not properly adjusted or even not properly built.

I assume you are not a technical guy, so you'll need somebody to check if they are correctly built and do some adjustments.

[Dennis Hui]

Hi Pyro2006,

They should perform similarly provided they were properly built.
Something is definitely amiss here. Furthermore, the original
Aleph2 schematics does not show any adjustment. (e.g. pots)

Do you have any instructions from these kits? If you do,
perhaps you can pull out the schematics and start by
seeing if is faithful to the original.

It wouldn't surprise me if there are parts stuffing errors.

Cheers,
Dennis

[steenoe]

diy mail order shop overseas

he probably did 10 - 15 sets of these in a row

Sorry to mention it, but it sounds like those kits are from one of those companies, ripping off Mr. Pass.

Steen.

[Stefanoo]

right....i think somebody should be doing something to stop those people!!!!

if i were Mr. Nelson Pass i would be veeeeryy mad..... and disappointed

[pyro2006]

well, the whole schematic for Aleph2 is open so I don't know if there is any real legal and IPR problem. However, they're not delivering what they're promising commerically is a business issue, just like any others

this is just like any diy project that fails, and many do, I surely won't think the design was not good in the first place, as the Aleph2 have been sold many times before as a product working properly

[GRollins]

It's the "sold" part that's the problem. It's illegal to make a profit on an Aleph without a marketing agreement in place with Nelson.

Grey

[steenoe]

well, the whole schematic for Aleph2 is open so I don't know if there is any real legal and IPR problem.

I do know! I wont try to explain anything, but you are way out, ripping off!! Publishing a schematic, doesnt mean that everyone can make a living from it!! The company, that sold you the kit....he-he.... should help you out!! Sorry!!

Steen