Aleph mods for quad 57?

[jonk]

I’ve gathered up all the parts (about a year ago) for the construction of a pair of aleph 2's. Since then I’ve acquired a very late model pair of Quad 57’s, which I love. A pair of Aleph 2’s is way overkill for my quads power wise. I was thinking of downsizing my 2’s to a pair of 5’s. Buy running a choke input I could get the rails down in the 30's V. My heat sink calculations gave me just enough for a 2 so I was thinking….
Would an over biased 5 sound better than a stock 2?
Are there any other changes that would make the amps work better with the quads weird loading?
Is there any advantage going to LCLC supply?
Any advice would be appreciated.
Thanks
Jonk

 

[stokessd]

I've run my Aleph 3 on 57's, 63's and my homebrew ESL's. And it just doesn't sound as good as other amps on any of these speakers. On monkey box speakers (cone and dome), the aleph 3 is magic! But there's something with the ESL load which doesn't agree with that little amp. I'm currently using a rebuilt pair of Heathkit W5M's on my panels.

I'd love to get my aleph 3 performing to it's cone and dome level on my ESL's.

Sheldon

 

[13DoW]

Power requirements to drive 57s

jonk,
have a look at these comments on the power requirements to drive 57s.

Regards
13th Duke of Wymbourne

http://db.audioasylum.com/cgi/m.pl?forum=mug&n=20883&highlight=wymbourne&r=&session=

 

[audionut]

In regards to the Aleph 3's driving the low impedance speakers...I have parralleled Aleph 3 channels together and they sound pretty good...I would think you would get better drive capabilites with paralleled channels and NP says that Alephs do pretty well being paralleled.

I thought the music got warmer and big orchestral passages come out better...and in general...more magic

 

[jonk]

Thanks for all the replies.
I was hoping someone had the magic solution like just use 4 outputs per at 32 volts and change two values of R and all will be perfect. Guess I’ll have to do it the hard way (or find a new tube amp project).

 

[13DoW]

Jonk,

looking at the schematic for Aleph3 it has +/-25V rails and the output is biased at ~2A DC. My suggestion would be to tweak the rail voltages to +/-35V and up the output bias current to ~ 3.25A (perhaps add one output device and one more current source device). This will allow the aleph current source to swing +/- 6A.
I have never built or even heard an Aleph so take my comments as someone cheering from the sidelines.
I'll certainly defer to Sheldon who has heard 57s driven by Aleph30. I don't know why it wouldn't work well with 57s. Maybe it does and you come back to personal preference - perhaps the 57s allow a lot more amplifier character through because they don't add their own boxy colorations. With a box speaker you want less amplifier character becasue the box has plenty of it's own.

I lent my nieghbour my CDP and power amps to give him a bench mark for upgrading. Thus the only difference was his box (Energy) speakers vs. 57s. I was taken aback by how much character the box speakers add. Just my $0.02, but whatever you drive them with I think 57s will give a lot of pleasure.

Regards
13th Duke of Wymbourne