Altec 604 Amp pairings

Fran604g

Just Call Me Junior
Thank you! Can you see the cap values? This looks very similar to the stock 604G exovers I rebuilt last year, but I assume there should be differences. Here's a shot of one before complete disassembly and rebuild.
 

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A few years back, I heard a pair of of 604-8G drivers in 612 cabinets powered by the original “Dolly” EL84 SEP amp that @Redboy built. It was a sweet sounding combination. I prefer SET to SEP but I could easily live with that combination for the rest of my days.
 

je2a3

Senior Member
Not quite 604 but close enough... these were the amps I used with my Altec 605B in the attic.

L>R: SE71A, SE10 + SE2A3
 
Thank you! Can you see the cap values? This looks very similar to the stock 604G exovers I rebuilt last year, but I assume there should be differences. Here's a shot of one before complete disassembly and rebuild.
I can’t see the cap values without taking it apart. Maybe I’ll have time to check it out later
 
I've run quite a few amps through my 604-8gs, reconed by GPA. Let's see....
-The little Cooncident Dynamo - single ended el34 amp.
-Line Magnetic 518ia (twice). Single ended 845s.
-Art Audio PX25 - dual mono construction SE PX-25 (beefed up 2A3). It was the same amp featured on the Glow on in the Dark blog. God I loved that amp.
- Mcintosh MC30
- Mcintosh MC225
- Restored/upgraded Scott 299b with 222c OPTs
- Allnic A1500 300b
- Kingko KA101 el84 amp
- Audioromy 828a - an 829B/GU29 based china manufactured amp
- Curtis Mathes push pull el84 console amp that's been gone over. About to strap it for triode operation and see what happens.,
- Sylvania "Amp 400-3" single ended 6V6 console pull I'm in the process of restomodding into hopefully something special.

Out of all these, the PX25 had by far the most magic. Still kicking myself for selling that one. Makes me think my first real top to bottom scratch build should be a SE 2A3.

The Scott sounds exceptionally good. The Allnic is good, but doesn't wow like some of the others have.

The Mac stuff was great, even exceptional, but I don't miss it if I'm being honest.

Line Magnetic wasn't a good pairing for me. Too much unusable power was part of it. The other was the tone. The 845 in that amp has a bite that didn't compliment the Alltecs - too forward for me. It was fanatic on Harbeths though.

The Allinc is great.... probably not top tier.

I'm not sure I'll ever buy another commercial amp again. I guess for the same reason I don't order steak unless I'm at someplace like The Capitol Grill in DC. Why pay 10x more for something you can make better at home?

Not to hijack, but as it relates to 604s... unless I can find a thread where this issue is already being discussed, I'm about to start a thread on 604 enclosures, big ones. Wondering if anyone has gone bigger than the 9 cu ft of the 620 into 11-12 cu ft Shindo LaTour territory, or heard both. My cabs are original and rough, ... trying to decide between building a nice new pair of 620s or something substantially larger. Found myself looking up plans for the Jensen Imperial folded horn the other night and need to be talked off that ledge. Excuse typos - on mobile.
 

Andyman

Junior Member
Would love someday to do a amp what was switchable between 45 and 2A3.

Years ago a local friend George F. let me borrow his amp and I'm pretty sure it was 2A3/45 switchable. I don't think he still has it, as it was for sale. It was a nice amp, but it do enough for me to pull the trigger and upgrade to it from my Almarro 205 cost wise.
 

charles hidalgo

Not a nobody
I have owned a few 604's over the years and have used everything from 3/4wpc- 30wpc in tube power to some PASS LABS SS stuff from around 8-30wpc. Tube types have been 1626, 2A3, 42, 45, 46, 47, 300B, 6l6, 6v6, KT88, EL34, EL84, off the top of my head with 6C33C, 6CB5A, and F2A tube type builds almost ready. For myself the best sounding are the 45/46, 300B, and EL84, with some amazing recent listening with different 6l6 and KT88 type tubes. Of course then there are rectifier, driver, and input tubes but that's another story. I had a a 1626 build running last week and listened to it for a few days and I was blown away. Though I kept wanting more power on certain rock music it was a great listen with lots of Jazz being really enjoyed at surprisingly high volumes for only 3/4wpc. I cannot recommend the EML 45's enough also.

Here's some of the keeper amps I use and really enjoy..

Left to right on the floor: Tubelabs SSE for 6l6, 6v6, EL34, KT88 etc, Bottlehead Kaiju 300B, James Burgess 45/46, Clementine version Darling 1626, James Burgess 45/2a3, and up on the amp stand (upper right) an Eddie Vaughn "Carina" EL84 which is amazing, with a few EL84 PP amps not pictured. I have a Dynaco SCA-35 Stereo35 clone from diyaudio with 7189's that is a bit noisy at idle but sounds way better than one would ever believe. So many variables.

IMG_3970resize.jpg
 
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Audionut

Next Round Is On Me
Great thread. I'm also using a 2A3 SET amp (Bottlehead StereomourII) with GPA604's and they seem to pair up nicely although I have nothing else to compare the amp too. Maybe a couple of MonAmours in the future will change that. ;-)
I have Bottlehead Paramount mono blocks that I am very happy with, but I do find myself looking at the MonAmours on occasion too.
 
At the risk of it needing its own separate thread, what would constitute a 'better' 2a3 amp? Kit or no kit. I'm very much a novice when it comes to these things and looking at circuits or design considerations doesn't really mean much to me, although I'm eager to learn.
 
At the risk of it needing its own separate thread, what would constitute a 'better' 2a3 amp? Kit or no kit. I'm very much a novice when it comes to these things and looking at circuits or design considerations doesn't really mean much to me, although I'm eager to learn.
One question, many and diverse answers. Even for the very experienced and scientific, personal beliefs and heuristics are strongly at play.

I guess this is why I like to try stuff and see. But I wrestle with it, often - that is a story for another time. I reckon a fine example of almost ant approach can get you something nice, but some will be a better match sonically than others. I like, with a little bit of help, scratch design and build. I also find it very difficult sometimes. It is not for everyone, and wasn’t for me initially, and still isn’t for designs heavily loaded with actives, and wouldn’t be if I was more scared of burning some $. Fear of “failure” still kicks in on occasion. Yes, I know consciously it is a learning experience and step towards a success, but…

If you want a nearly-assured result and relative ease: go for a kit with support - it will still be a challenge and very rewarding... and you should develop the basic skills and learn a solid way of building. Willing to give up some ease: maybe try a proven design, with some help - you will find that here, but I do feel for Paul carrying the load, at times. Great guy - so willing to help and share knowledge. Want to try something a little different, got some skills, and able to risk the cost of failure, and not tight for time: design and build scratch.

Be ruthlessly honest with yourself, choose something that suits your risk tolerance and sounds like it is in your sonic realm, then just go for it. What matters is doing what suits you, you find enjoyable, and learning from it. There is no right and wrong, better or worse. Nothing special. Nothing that isn’t special. Just make sure it is built safe and safely.

Edit: cleaned up my brain-dump a little.
 
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One question, many and diverse answers. Even for the very experienced and scientific, personal beliefs and heuristics are strongly at play.

I guess this is why I like to try stuff and see. But I wrestle with it… I reckon a fine example of any one approach can get you something nice, but some will be a better match sonically than others. I guess this why I like, with a little bit of help, scratch design and build. I also loathe it sometimes. That is not for everyone, and wasn’t for me initially, and still isn’t for designs heavily loaded with actives, and wouldn’t be if I was more scared of burning some $. Fear of “failure” still kicks in on occasion. I know consciously it is a learning experience and step towards a success…

If you want a nearly-assured result and relative ease, go for a kit with support; will still be a challenge and very rewarding... and you should develop the basic skills and learn a solid way of building. Willing to give up some ease, maybe try a proven design, with some help - you will find that here, but I do feel for Paul carrying the load, at times. Great guy. Want to try something a little different, got some skills, and able to risk the cost of failure, design and build scratch.

Be ruthlessly honest with yourself and try something that sounds like it is in your sonic realm, that suits your risk tolerance, and just go for it. What matters is doing what suits you, and learning from it. The is no right and wrong, better or worse. Nothing special. Nothing that isn’t special.
Thank you for your wise and thoughtful advice. Much appreciated! The last paragraph really resonated with me.
 
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