Pull 2 tubes on the 2466?

[SteveD]

The ohm selector is used as normal with two KT88s; the output TX's primary inductance is actually quite well matched to a pair of KT88s.

I wouldn't put four KT88s in a 2466; it's not a good electrical match on so many levels.

6550s are a similar deal to KT88s; I would recommend a pair only.

[weiht]

Hi Steve, can the kt8c be used instead? Heard its as gd a direct replacement for kt66 as they r almost identical

[foureyedpunk]

So if I understand this right...2 KT-88's would work fine while leaving my ohm selector set at 16 ohms going into the 16 ohm input on my speaker cabinet.

How bad would it sound if I wanted to drop them in to see how they sounded w/o biasing? Would damage occur???

Thanks

[MKB]

Just tried the 2466 with a pair of KT88s in the output and was very impressed with the result. :) This is a viable option for anybody who wants a different sound characteristic from their 100W Vintage Modern head. The sound was more edgy and crunchy and the dynamic reaction to the guitar volume pot was retained. The power amp gives a bit more linearity at higher volume which some people may prefer or not; Kt66s have a fatter mid and smoother treble response. Both valve types yield good tones, it's just a matter of personal taste which suits you better. Personally I prefer the KT66s but I know there will be people who prefer the KT88s; especially those who like EL34s.

There are no mods to be done to the PCB. Bias for the KT88s can be set at 60 to 64mV per valve (at Connector 10 pins 1 and 3). There is no real significant reduction in power and therefore volume to be had with this configuration, just a different sonic texture. The amp will live quite happily with either configuration.

Steve, did you get a chance to measure the power output with the pair of KT88's? At first blush I'd think it would be approximate to the KT66 quartet, all else being the same (but this is a guess). Just wondering if the two KT88 solution would give a power drop to those wanting less power from their 2466 head.

[SteveD]

So if I understand this right...2 KT-88's would work fine while leaving my ohm selector set at 16 ohms going into the 16 ohm input on my speaker cabinet.

How bad would it sound if I wanted to drop them in to see how they sounded w/o biasing? Would damage occur???

Thanks

The amp would be biased very cold and most likely sound pretty bad.

[SteveD]

Just tried the 2466 with a pair of KT88s in the output and was very impressed with the result. :) This is a viable option for anybody who wants a different sound characteristic from their 100W Vintage Modern head. The sound was more edgy and crunchy and the dynamic reaction to the guitar volume pot was retained. The power amp gives a bit more linearity at higher volume which some people may prefer or not; Kt66s have a fatter mid and smoother treble response. Both valve types yield good tones, it's just a matter of personal taste which suits you better. Personally I prefer the KT66s but I know there will be people who prefer the KT88s; especially those who like EL34s.
type of tone while retaining the dynamic reaction
There are no mods to be done to the PCB. Bias for the KT88s can be set at 60 to 64mV per valve (at Connector 10 pins 1 and 3). There is no real significant reduction in power and therefore volume to be had with this configuration, just a different sonic texture. The amp will live quite happily with either configuration.

Steve, did you get a chance to measure the power output with the pair of KT88's? At first blush I'd think it would be approximate to the KT66 quartet, all else being the same (but this is a guess). Just wondering if the two KT88 solution would give a power drop to those wanting less power from their 2466 head.

A duet of KT88s gives about the same power output as a quartet of KT66s so there's no discernable difference in volume, just tone. Interestingly, the 88s make the Vintage Modern sound a little closer to the EL34 type tones while retaining the dynamic reaction. Conversely, EL34s sound pretty crap in the Vintage Modern and lose the dynamic feel. :(

[marshallmellow]

Hi all,
New to the forum. Just purchased a 2266, and really like the amp. Could the KT88's be used in a 2266, or is there another output tube that would yield the same results in the 2266 tonewise, that the KT88's do in the 2466 : ?

[SteveD]

Hi all,
New to the forum. Just purchased a 2266, and really like the amp. Could the KT88's be used in a 2266, or is there another output tube that would yield the same results in the 2266 tonewise, that the KT88's do in the 2466 : ?

Not a recommendation of mine but you could try it if you biased them cold.