Modulus-686: 380W (4Ω); 220W (8Ω) Balanced Composite Power Amp with extremely low THD

[tomchr]

Here the caged version is actually $3 less(!) Last year when I built my amps, I recall the cage adding maybe $5. Weird with the difference across the pond.

Tom

 

[kberge]

That surprises me. When I lived in Europe, I ordered from RS on occasion. I didn't have a VAT number. Of course, that was a while ago so their policies could have changed. I've bought from Farnell as well. Most of my purchases came from Aarhus Radio Lager and Vejle RC Elektronik, both in Denmark. Aarhus Radio Lager was bought by Elfa in 2006, but to my knowledge they're still around.



Mouser, Digi-Key, Newark, and Jameco to name a few will happily sell to private buyers.

Tom

PSU example: It can be delivered from here in EU/Norway:
https://www.elfadistrelec.no/search...&sid=db68a52517b1674933380985fd1227e561acfa3b

 

[JustLiSten]

Premières impressions d'écoute

Hello Tom,
Some photos and my first listening impressions.
This is of course a provisional layout, that's why the power cables are
still long.
I have not yet decided if I keep a single double mono block or 2
separate mono blocks.
The bass is very beautiful and very tense, the whole is dynamic, the
stereo image beautiful and ample. I have not yet pushed the amp too
much, to its limits.
The medium is not aggressive, even on digital signals. Maybe a little
less warm than on my Primaluna tube amplifiers, but we feel a real
impression of available power.
I haven't tried vinyl records yet.
4 ohms speakers with 2x36 volts power. Unbalanced input.
More news in a while.
Thank you for the technical support and this great achievement of
amplification cards.
Regards,
Jean-Luc

An externally hosted image should be here but it was not working when we last tested it.

An externally hosted image should be here but it was not working when we last tested it.

An externally hosted image should be here but it was not working when we last tested it.

 

[zman01]

Jean-Luc,

You images are not showing - can you please try to attach them by going into "Go Advanced" and adding them with "Manage Attachments" under "Additional Options"?

Thank you sharing some early listening impressions. I have a Modulus-86, and my impressions are similar.

 

[JustLiSten]

zman01,
Where is Go Advanced ?

 

[zman01]

Jean-Luc,

Please click "Edit" on your post and you should find it.

 

[JustLiSten]

Premières impressions d'écoute

Hello Tom,
Some photos and my first listening impressions.
This is of course a provisional layout, that's why the power cables are
still long.
I have not yet decided if I keep a single double mono block or 2
separate mono blocks.
The bass is very beautiful and very tense, the whole is dynamic, the
stereo image beautiful and ample. I have not yet pushed the amp too
much, to its limits.
The medium is not aggressive, even on digital signals. Maybe a little
less warm than on my Primaluna tube amplifiers, but we feel a real
impression of available power.
I haven't tried vinyl records yet.
4 ohms speakers with 2x36 volts power. Unbalanced input.
More news in a while.
Thank you for the technical support and this great achievement of
amplification cards.
Regards,
Jean-Luc

 

[JustLiSten]

@zman01,
Thank you, done.
I post a new because i c'an't edit my first ...

 

[needsp]

Hi Tom

[/Another option for those who want ±36 V would be the Connex SMPS800RE. Just have Cristi make you a custom ±36 V version. He charges an additional $8 for that.
Note that I have not tested the SMPS800RE with the Modulus-686, but see no reason why it would not work. As long as you get the ±36 V custom version, that is. QUOTE]

For a stereo build, I assume I'd need 1 Connex supply per channel. Would they work with your MeanWell supply boards? Again, one per channel?

Thanks

Paul N

 

[tomchr]

Hello Tom,
Some photos and my first listening impressions. [...]
Thank you for the technical support and this great achievement of
amplification cards.

You're very welcome. Thank you for sharing your build pictures so far. I hope we get to see the finished amp as well. Nice work!

Pardon my belated response here. It seems DIY Audio has stopped sending out the thread update notifications. Time to refresh those.

Another option for those who want ±36 V would be the Connex SMPS800RE. Just have Cristi make you a custom ±36 V version. He charges an additional $8 for that.
Note that I have not tested the SMPS800RE with the Modulus-686, but see no reason why it would not work. As long as you get the ±36 V custom version, that is.

For a stereo build, I assume I'd need 1 Connex supply per channel. Would they work with your MeanWell supply boards? Again, one per channel?

They would not. They would work with the ISS, however.

I would go with one SMPS800 per channel. You can share the ISS between the two SMPSes.

Tom

 

[AndyTather]

Hi All,
My dual mono block Mod-686 build is coming together, slowly.

Did some initial testing and found no problems with interference, a little surprising as it is quite compact in places.

Still trying to decide how to wire the LED in the front panel switch before the lid goes on permanently.

More pics later.

Andy

 

[tomchr]

Holy crap! That is an impressively compact build there! Nicely done.

Tom

 

[poseidonsvoice]

Andy!

Fantastic compact build! Super quality too. More pics please!!

Best,
Anand.

 

[pinnocchio]

Beautiful build!!!

Do

 

[killie99]

I've just purchased all the bits from Tom to build a dual mono in one case, I've got a lot to live up to! What value Toroidy transformers did you use?

 

[AndyTather]

Toridy transformers are TSAS 400VA - 2 X 25 V

Would have gone bigger if I could

I have made a little photo blog of the entire build journey which maybe of interest. Just tidying it up and fixing links etc then I'll post it here.

 

[AndyTather]

Beautiful build!!!

Do

Can't think where the pics/technique for flat mounting came from

Thanks.

 

[killie99]

Where did you get the transformer mounting plates, I like them. edit Ah, found them on Toroidy, can't see how to buy them separately though, looks like they are only available with the supreme audio transformers. Also, what case did you use?
I had ordered one of these from China but it appears to have got lost on it's way to me and the price is now £40 more than when I ordered so looks like I'll be getting one from Modushop instead, pity as it's a nice case.

 

[454Casull]

Where did you get the transformer mounting plates, I like them. edit Ah, found them on Toroidy, can't see how to buy them separately though, looks like they are only available with the supreme audio transformers. Also, what case did you use?
I had ordered one of these from China but it appears to have got lost on it's way to me and the price is now £40 more than when I ordered so looks like I'll be getting one from Modushop instead, pity as it's a nice case.

They couldn't get you a replacement instead of a refund?

 

[tomchr]

Where did you get the transformer mounting plates, I like them. edit Ah, found them on Toroidy, can't see how to buy them separately though, looks like they are only available with the supreme audio transformers.

I'm pretty sure the "mounting plates" for the transformers is an option when you order. It's not a separate item. I bet it's secured to the transformer with the potting compound.

Tom