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Old 13th November 2012, 04:24 PM   #1301
Marra is offline Marra  United Kingdom
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Quote:
Originally Posted by 6L6 View Post
Marra -

That is fantastic news! Welcome to the initiated.

It was actually meant to be a quote from Albertnl's post which did'nt quite work right.I've been infected for years and get the shakes if I haven't a soldering iron close to hand
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Old 13th November 2012, 04:34 PM   #1302
6L6 is online now 6L6  United States
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LOL!

Regardless, we all know that it's an addiction with no known cure.

(I am currently making an order to make a 'universal' external PSU for my Pass/Firstwatt amps. A box with the transformer, bridge, caps, etc... so I only have to pay for/build one powersupply, and just make amp channels on heatsinks or in smaller chassis. Not having to buy a PSU for every amp means that I can try more of them! Hooray!)

See, it's not just you.
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Old 13th November 2012, 05:01 PM   #1303
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Quote:
Originally Posted by 6L6 View Post
LOL!

Regardless, we all know that it's an addiction with no known cure.

(I am currently making an order to make a 'universal' external PSU for my Pass/Firstwatt amps. A box with the transformer, bridge, caps, etc... so I only have to pay for/build one powersupply, and just make amp channels on heatsinks or in smaller chassis. Not having to buy a PSU for every amp means that I can try more of them! Hooray!)

See, it's not just you.
so a +/-23-24V PSU?
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Old 13th November 2012, 05:11 PM   #1304
Marra is offline Marra  United Kingdom
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Yes a seperate p/s is an excellent idea.I have a set of PD's Aleph J boards assembled and waiting in the wings but I'm going to have to disassemble my F5 to put it together.Was thinking of just swapping out the pcb's and heatsinks but the last quote for heatsinks unanodised was 300GBP's talk about rip off Britain!
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Old 13th November 2012, 05:52 PM   #1305
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Ideally one case only having large heatsinks, a multitapped transformer and high enough voltage rated caps of consequent capacitance might serve for most of amp boards to try including classA, AB, Or even chip amps.
You'll end with many holes into the heatsinks though is that a problem?
If you can't stop building amps it will go cheaper.
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Old 13th November 2012, 06:39 PM   #1306
6L6 is online now 6L6  United States
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Quote:
Originally Posted by AudioSan View Post
so a +/-23-24V PSU?
Yes, exactly. Nothing complicated... merely oversized (600VA transformer) with 100,000uf per rail, convenient, (Speakon connections for the power umbilical) and in a nice box to look good.
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Old 15th November 2012, 04:03 PM   #1307
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Hi guys,

Today I finally connected my new Aleph J to my main system. It would take too much time to set up in my study, so I decided to take the plunge in the main system.
It replaces my Pass Labs built Aleph 3 and runs mid/hi on my 4 Ohm Magnepan MG3a's. Not an ideal marriage, but .... SHE SINGS!

First impressions (single ended input):
  • Dead quiet.
  • The sound is different.
  • It really draws you into the music.

I will not try to explain the differences at this stage, but just enjoy the music! After a week or so, when it is burnt in properly, I hope to be able to do some comparing and also try out the balanced inputs.

A friend of mine built a pair of Aleph 2 monoblocks for me about 6 years ago. I intended to use them in my main system because the Aleph 3 is a bit small for the power hungry Magnepans. While the 2's sound very nice, they could not match the Aleph 3 in sound quality and ended up in my study. Having just switched on the J it is interesting that I do not (yet) miss the 3.

Having built my first power amp I now plan to take the Aleph 2's apart
I have already seen that some parts could do with upgrading (Silmic caps, better internal wiring, small film caps in PSU, etc). I will try to get the 2's to sound closer to the 3. Depending on how the J settles down, I might end up converting the 2's to a jfet front-end, but will need serious help from you guys if I do!

Thanks everyone, I am a very happy builder!

Albert
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Old 15th November 2012, 04:10 PM   #1308
Zen Mod is offline Zen Mod  Serbia
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naah

it's easy - few Jfets and few bjts for cascodes
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Old 15th November 2012, 04:13 PM   #1309
generg is offline generg  Germany
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I know this feeling, to be a happy builder...... Good hearing!
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Old 25th November 2012, 08:04 AM   #1310
kroyin is offline kroyin  India
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I succeeded in stripping 1 F5 Chanel & replacing with Aleph J

Matched mosfet, jfet. ZTX critter.Here are my voltage readings

R7-4.92V
R8-8.94V (case of Zener not dropping 9.1V??)

R16-.521V
R17-.610V (??)
R18-.563V
R19-.557V

No voltage across R20/21/22/23???

Offset after 1 hour 27mV.Plays music, things which sound harsh with F5 are mellower.

Any concerns with the above???
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