[Escott1377]

I am running a pair of Prima Luna mono blocs that are bi amped to my tweeter and midrange.

I have a pair of Wyred 4 Sound mAmps feeding my woofers.

My analog side is Sounsmith Voice > VPI 1 Classic > Manley Chinook > amplification

Digital side is Logitech Squeezebox > Cary 100 t > amplification.

Pre amp is Manley Shrimp.

The Prima Luna came with EL34's, their brand.

I want to replace the output tubes on the Prima Luna.

The amps will accept just about any power tube excluding the EL84.

I am currently looking at EH KT88, EH KT90, Tung Sol 6550, and Golden Gate KT88.

I listen to jazz, rock, classical, a little bit of everything excluding rap on my 2 channel system.

Any suggestions or experience witht the above list?

I am not looking to break the bank as I understand the output tubes make the least sonic impact.

I use all NOS tubes in my other devices, using Mazda 12AX7's on the input stage of the Prima Luna.

Any help or suggestions is greatly appreciated.

[rpf]

I thought the KT90s were a bit thin sounding and the TS 6550s had too much bass emphasis (maybe this won't matter with your bi-amp setup).

The Genalex KT77s are somewhere between an EL34 and a KT88 in sound, though ultimately I found them less satisfying than either of the other tube types. There seems to be a discontinuity in the frequency bands.

The Genalex KT66 re-issue on the other hand is probably my favorite power tube: coherent, tonally accurate, extended and balanced in frequency response, and with an immediacy and refinement that is similar to SETs.

I haven't heard the EH KT88s and I've never heard of the Golden Gate KT88s.

I like the Genalex Gold Lion (is this what you're referring to?) KT88 re-issues but I prefer the Penta KT88SCs for their refinement.

None of these are particularly expensive.

[Escott1377]

Golden Gate are from China and have gotten good reviews on the Internet. 

They are cheap, on EBay right now for $100 / Quad.

I went with the EH KT88's.

I have some NOS 6L6's headed my way as well.

Thanks.

[Ericus Rex]

With my amps, the output tubes have the MOST impact on the sound.  No experience with your Prima though.

[rpf]

The Prima Lunas have auto bias, which apparently - from both my limited experience and a couple of reports I've heard/read - ameliorate the differences in sound between power tube types.

[Escott1377]

The Prima Lunas have auto bias, which apparently - from both my limited experience and a couple of reports I've heard/read - ameliorate the differences in sound between power tube types.

My only experience with swapping power tubes is when I was running Manley Snappers.  To me, Manley gear has a very distinct sound and I did not hear much in the way of differences between power tubes.

We shall see, like I said I will have an octet of NOS 6L6's and an octet of EH KT88's here shortly.

[Steve]

I am running a pair of Prima Luna mono blocs that are bi amped to my tweeter and midrange.

I have a pair of Wyred 4 Sound mAmps feeding my woofers.

My analog side is Sounsmith Voice > VPI 1 Classic > Manley Chinook > amplification

Digital side is Logitech Squeezebox > Cary 100 t > amplification.

Pre amp is Manley Shrimp.

The Prima Luna came with EL34's, their brand.

I want to replace the output tubes on the Prima Luna.

The amps will accept just about any power tube excluding the EL84.

I am currently looking at EH KT88, EH KT90, Tung Sol 6550, and Golden Gate KT88.

I listen to jazz, rock, classical, a little bit of everything excluding rap on my 2 channel system.

Any suggestions or experience witht the above list?

I am not looking to break the bank as I understand the output tubes make the least sonic impact.

I use all NOS tubes in my other devices, using Mazda 12AX7's on the input stage of the Prima Luna.

Any help or suggestions is greatly appreciated.

I have performed some testing and comparing KT88s and 6550s. Self biased, so idle plate current will vary slightly, but not much. My system is extremely revealing, so what appears to be night and day may not be in another system. My conclusions are relative to each other brand tube listed, not in absolute terms.

EH, Winged C, SED KT88s,,,,,, Winged C, new manufacture Tung Sol 6550s.

EH were by far the fullest sounding of the tubes mentioned above. Highs were less than other brands, by far.
SED KT88s were much leaner, just very slightly fuller than the Winged C KT88s and 6550s. A little tweaking could adjust either.
New Manufactured Tung Sol 6550s were by far the leanest, thinnest sounding of the tubes mentioned above.

EH and new Tung Sols were opposites, so to speak. Middle would be the SED/Winged Cs. SED were so so close, I would go for them in my
system as the Winged C are so expensive, if one can tweak if necessary.

Overall, the brand chosen will depend, of course, upon your own system's requirements and tastes.

Cheers
Steve

[Escott1377]

I bought an octet of 6P3S from Ebay.

Supposedly NOS from the early 70's.  Minimal investment, took a while to get to SC from Russia.

I had them running for 2 days until I had to pack up my speakers to go back to the manufacturer for an upgrade.

From what I heard, I was very impressed with the cost / performance ratio.

The EH KT88's seem to be a little too much in my bi amp configuration.

The stock EL34's were too thin, seems like the NOS Russian tubes are the best fit so far.