KT-88 vs. EL34


Hi. I have a modified Jolida 502 amp (not my main amp) currently using KT-88s and formerly the similar 6550s. Some have suggested that this unit will sound even better, power hit aside, modifying to accept EL-34s. The mod is easy. Anyone find this to be true or is it just another myth? Thanks in advance, Andy8400.

andy8400
Hey,
Re: Some people say that say KT88s would be "better" than EL34s. Not sure, so subjective, and like the prior note above, also depends on amp design.

E.,g I have a PrimaLuna Dialogue HP Int. Amp, and have started out with EL34s, but even in triode mode, it sounds "dry" not sweet. and even sounds a bit thin in triode and ultra linear mode. so I'm going from EL34s to KT88s for more body, texture, timbre. Case in point, its hard to tell how the sound will be with certain tubes. Unfortunately, we just have to tube roll to find out.
I googled EL34 vs 6L6 and was surprised at how much info there was on such a specific topic, including YouTube videos of guitarists comparing them. Of course the tests were in regard to heavy metal guitar amps and not critical listening but I think I preferred noromance's 6L6 recommendation. Should be fun to try since I have a nostalgic interest in the 6L6 anyway!

My question now is: how different, if any, are the bias voltage settings between the EL34 (which I think I know) and the 6L6 (which I don't know)? Are they truly drop-in replacements? Thanks, Andy

"I am currently using Canton Karat M70s, woofers facing out. Not too efficient and 6 ohm average. Current amp is SS, a B&K AVR-307 (150w x 7) in two channel analog mode, used for stereo only."

Since you already have the gear, you might as well try a vertical biamp. Remove the jumpers on the back of the speakers and use 2 channels on the amp for each speaker. 4 channels, not 2. It may make a big difference, or not. Results vary.
Thanks for your thoughts, sfall. As it turns out, I had already bi-amped these speakers in the past, more for control than for power. I had used different amplifiers and not all four from the B&K and for the following reason... To use 4 or any more than 2 channels from the B&K, you must be in the digital mode, that is to go through the amp's DSP. Although virtually indistinguishable from 2 channel, I wanted to keep my signal path pure analog which bypasses the DSP altogether.

Also, my listening room is small by most standards and the 150W per channel from the B&K's humongous power supply is an overkill as it is. In fact, to handle the myriad problems a small listening room provides, I use a 31 band equalizer to tailor the sound... particularly the bass bloat from the nearby room corners (and for minor adjustments to the rest of the audio spectrum).

You may be thinking that the Canton Karats are too much speaker for a small room and you'd be right, especially considering the smaller model speakers that are available. However, it's what I have to work with so it is what it is. Thanks again, Andy
You should be able to swap in 6L6 for EL34 as long as you can adjust the bias AND you get the GTB versions as they can work with higher plate voltages AND as long as your amp can work with these tubes in the first place.