re-tubing CJ LP70s

The cheapest route would be to change out the Telefunken 12AX7 tubes in the Calypso to something not has solid state sounding as the telfunkens. You could try Mullards, Amperex or one of the NOS 5751 tubes. That's what I did. If this doen't work then you could change out the tubes on the amp. There are many threads on Audiogon or AudioAsylum about changing the Calypso Tubes.

I have tried a variety of 6550 varients in my CJ PR 8A's from EH, Svetlana, NOS Tungsols and others and for the price, sound, and reliability the SED Winged Cs are my tube of choice as of a lot of other Audiogoners.

"...3D, liquid, sweet mids..." - not the 6550's strong suit; EL34, yes.

After the NOS GE6550A - CJ ran out of 'em during the middle of Premier 12 production - I'm with Bbro and SED Winged C 6550C.

Regarding the 6DJ8/6922/7308 driver - here's a good opportunity to have some fun tube rolling. I've yet to hear a contemporary member of this family that meets up with any of the better NOS. Amperex Orange Globes are a safe choice. From current tubes, the Electro Harmonix 6922 is worthy and inexpensive.

Thanks to you all.

For the 5751, there are many variations. I was looking at eBay, MDS, can you please elaborate which one it is? i know the 3 mica ones are the one to look for. then the black plate ... then I get confused.

The NOS tungsol is so $$$, that's completely out of the question. I will definitely go with the Winged Cs.

just a side question, how do you determine if an amp is underpowered for the speaker by listening?

Keshui
You could try the GE 5751 tripple mica or RCA 5751 tripple mica either black plate or gray. I have the black plate but not sure if the gray plate sounds a lot different. A matched pair of these are typically less than the 12AX7 tubes. These are not too hard to find in a matched pair. You might check to see what the gain blocks are set on the Calypso and lower the gain if the tubes are noisy.

My choices for what you want
1. Amperex 12Ax7 "D" Getter
combined with
Amperex 7308 White Label Holland
Amperex 6922 PQ " " " US
Seimans EI88CC
2. Amperex 12AX7 Halo Getter White or Orange
Amperex 7308 PQ White Label US or USN-CES 6922
Seimans EI88CC
3.Mullard CV 4004
Amperex 6922 PQ White or Orange
Amperex 7308 PQ Holland

Change all the 6922 tubes out for a nice set of amperex or mullard 6DJ8 and it will help. You can try to install KT88 in it also but I have never tried that and don't know if that will improve on the SED 6550.

Not sure why people are mentioning 12ax7 tubes. The LP70 uses 6922. I believe the 5751 are a lower gain so be careful.

I was thinking the Mds school of rolling the Calypso tubes first and didn't state that, sorry!!!

Any of the Amperex 6922's/7308's would be great in the C/J driver sockets.

Jtimothya,

In my post above I mentioned my preference for SED Winged C 6550 tubes in my CJ Premier 8A's. However FYI I had already scheduled to have my PR 8's converted to the XS triode version utilizing EL 34's tubes, for the reasons you mentioned in your post. I have 4 quads of original NOS TESLA EL 34s on hand which I aquired for the conversion. I am very anxious to hear the change. I am also having Teflon V-Caps installed while I am getting the XS conversion done.