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Old 21st July 2013, 07:58 AM   #1
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Default COPLAND CTA 401 - upgrade of components ?

Hi ,

This is my first post.

I have a Copland CTA 401 hybrid amplifier.

Its from the early 90s.

NOW: I have been recommended to upgrade some of the capacitors in this amp. Especially the yellow caps ( like on the picture )

Should I let it be, or should I do this upgrade ?

Any other upgrades I should think of for this amplifier ?
( I have just changed the tubes )



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Old 22nd July 2013, 09:01 AM   #2
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If it manufactured in '90s you should consider replacing electrolytic caps first, then perhaps the other. Have tubes been replaced since then?
BTW, why do you want to do it?
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Old 22nd July 2013, 11:42 AM   #3
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Hi !

Thanks for the replay .

To answer your question : the tubes has just been replaced .

More info about the new tubes :

Two : SED SVEL34
Three : JJ ECC803s / Hi-Performance 12AX7 Gold Pin
Two : JJ ECC802s / Hi-Performance 12AU7 Gold Pin


To answer your BTW question :

Im in the process of finishing a pair of vintage altec speakers s and just want the copland amplifier to do the best job it can driving these speakers.

I must admit that I have not much knowledge about tube amplifiers. This is why I am posting - just wanted some opinions if I should do any upgrades on this amp.
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Old 23rd July 2013, 10:41 AM   #4
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OK.

Not much replays here....

More information :

I have not much knowledge about tube amps : correct

, but I have done upgrades on vintage Quad solid state amplifers.
I have also done quite a lot upgrades on vintage speakers.

I have thought a little bit : and have a new question :

I have a pair of Altec 604 E Duplex speakers in DIY 612 cabinets.

I have tested these speakers with two amplifers ; I found the sound in the Copland CTA 401 most satisfying in my ears. The other amp I tested these speakers with was a solid state amplifier.

SO: my question is as follows : Should I do upgrades on the Copland CTA 401 hybrid amplifier , or should I by myself a tube amp for these speakers : like the 2A3 tube Stereomour amplifier from Bottlehead ?


One more question :

What difference in sound will I experience with going completely tube on this system ? the 604E speakers are rated around 100 dB.



Any inputs or help will be much appreciated .


- tralalalala
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Old 25th July 2013, 11:55 AM   #5
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Is there a reason you keep wrtitng "hybrid"? I have found a CT 401 schematic and there are tubes in the audio path, not counting SS rectifiers. Just curious.
As to choosing SE vs. PP amp you should listen to the former. My personal recommendation is SE amp. 2A3 SE amp should be sufficient driving +100dBm speakers. I use 6C4C (6B4G equiv - 3,5 W) parafeed SE amp for 90dBm speakers and volume knob is turned to 2/3 max and is loud enough.
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Old 25th July 2013, 12:43 PM   #6
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Hi Yagoolar!

Thank you so much for your replay.

Searched around on the net... I have always thought it was an hybrid.

Copland do make hybrids. It looks like mine is not. Is it a PP or push pull?

One more thing... Cant find it but Im sure I have the service manual
For this amp somewhere...

I have done research on SE amps before, but never heard one.. found the bottlehead stereomour and the FI X : with both 2A3 tubes...
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Old 25th July 2013, 01:26 PM   #7
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Attached see the schematic. Definitely push-pull AB operation
Amplifier Schematic Diagram
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