KT-120s in LP70S

[Sunnyboy1956]

Winged C 6550s and Gold Lion KT 88s

[Puma Cat]

Originally Posted by ronenash

Which 6550 and kt88 did you use? I was thinking of trying Gold Lion KT88 in my LP125mSE.

I don't know about the LP125M, but my LP70S didn't like the GL KT88s at all.

[ronenash]

If it did not work well in the LP70s I am sure the results will be similar in the LP125M.

Thanks for the info.

[Puma Cat]

KT120s, on the other hand, work GREAT!

[Sunnyboy1956]

Ronenash
If you want to swap the 6550s go all the way to the KT120s. Not aware of any CJ/ARC owner not happy with this change. OTOH the Gold Lion KT 88s were only a marginal improvement over the stock Winged C 6550s.
Pradeep

[ronenash]

I already have KT120's in the LP125m SE. Just thought of experimenting with something different. Guess not.

[Joe Appierto]

Originally Posted by ronenash

I already have KT120's in the LP125m SE. Just thought of experimenting with something different. Guess not.

Just curious: what are you using currently in the M8080 and 6922 positions? Have you tried rolling any other brands through?

[ronenash]

For the M8080 I am using the Mullard supplied by CJ. There are not many good option available for this tube. Most 6C4 tubes are microphonic and not very good. I purchased 4 sets of the M8080 from CJ (PV14 sets) which will last me a lifetime.

For the 6922 I tried many different ones and settled on the Matsushita 7DJ8 and the Russian 6n23p-ev. Both work very good and are reliable. I tried some Amperex 6299 D getter tubes which flashed in one of the amps when the amp was turned on (could not take the initial voltage). They stabilized after a few seconds but would not last long in the amp, I am sure.

[aldinohiend]

I suggest you replace the M8080 marked Mullard Mullard because they have nothing. I used the 6C4 Tung-Sol Jan 1944 (clear) or the Mullard EC90 (more amber). The best and the most balanced were the 6C4 Ken-Rad. Regarding 6922, I suggest the E88CC Philips SQ, absolutely preferable to all. For power tubes I have not had the opportunity to try the KT120 but I am so happy with the Tung-Sol 6550 reiussue that I bought less than 5 octets.

[Briz Vegaas]

Hi.
Anyone notice that the LP70 runs a lot hotter with KT120 tubes than with the standard set.. Maybe it's because I have the tube cages largely in place and others leave it open, but I found its pretty darn warm to the touch.

With the standard tubes and with cages in place it's no more than " pleasantly" warm, less than I was expecting anyway.

I'm thinking of only running the big tubes in winter or on cool days and risking no tube cages (keeping a close eye on the cats to start with ). I'm, not comfortable with electronics getting hot to the point where I could not happily rest my hand on the front panel, let alone the tube cages. I don't have air conditioning here and Brisbane summers (and now autumns) are 30 degree hot, what's that, low 90s in degrees F I guess.

What have others found, particularly comparing the standard to the KT120 tubes as its a good reference. My hot may not be your hot, if you get my meaning.