No, you are. That was not my initial inquiry. My initial inquiry has to do with tube amp kits, thanks.
A little later you stated that you can hear a difference of 8% power. Do you
still claim that or do you shuffle the cards instead ?
In order to take full advantage of these larger tubes, the output stage needs to be specifically designed for them. When you see an amp that can take KT88s or these larger tubes, you know it wasn't built for them because any amp that was designed to take full advantage of KT120s or KT150s would melt KT88s.
If I were a designer, I don't think that I'd design with tubes that only have a single source, though. It's pretty risky. Hopefully you can find one, though.
The other alternative is to design your own and by a stockpile of tubes so that if the New Sensor stops making tubes, you can keep yours going.
Personally, I'd just make more power with more common tubes in parallel. It accomplishes the same thing whether you have 60W plate dissipation in two bottles or one.
If I were a designer, I don't think that I'd design with tubes that only have a single source, though. It's pretty risky. Hopefully you can find one, though.
The other alternative is to design your own and by a stockpile of tubes so that if the New Sensor stops making tubes, you can keep yours going.
Personally, I'd just make more power with more common tubes in parallel. It accomplishes the same thing whether you have 60W plate dissipation in two bottles or one.
Actually I never said that. You're trying to put words in my mouth. I said I can hear less than 3dB difference. I never actually said how much less/more. You are assuming things for whatever reason. Don't be all butt-hurt just because I don't like your advice. That's gonna happen in life. Not everyone will agree with you all the time.
Thanks for the advice. ATM, I'm not versed in tube amp architecture to design my own amp. Only looking to purchase a kit already put together by someone who knows what they're doing in that regards.
It would probably be a lot easier to find an amp or kit at those power levels that uses common tubes with 4 power tubes per channel. That's what I'd look for. The big tubes look kind of cool but they aren't better than smaller tubes in parallel and it's going to be hard to find something that is really designed with them in mind.
Unless you can afford to buy a big amp like an ARC REF 150 that's designed using the KT120.
jeff
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And even then, the moment New Sensor decides that KT120/150 aren't making enough money and discontinue them, you are screwed.
That won't happen any time soon with KT88, 6L6, EL34, or tubes like that.
I wouldn't buy an amp that used these tubes unless I were very well off and losing thousands of dollars just wasn't a big deal to me. There just aren't any really good candidates to replace a KT120/150 in the event they ever go away.
This is why an SPL meter is a very helpful tool when making these sort of decisions. If one knows what sort of loudness peaks they’re hitting at the main listening position at a desired listening level, then one can more confidently walk back what sort of power requirements are necessary with a given sensitivity of speaker.
@Oscar: I did an online loudness test using sinewaves and I could not detect anything less than a 1 dB change in volume (.5dB increments). If your hearing can detect such small changes, I would be curious what the impedance vs frequency is of your speakers. I did look on your behalf but to no avail. A roller coaster impedance line is going to modulate the power output of a tube amplifier unless the crossover has been designed to be driven with the higher output impedances of a tube amplifier. Just something to be aware of.
@Oscar: I did an online loudness test using sinewaves and I could not detect anything less than a 1 dB change in volume (.5dB increments). If your hearing can detect such small changes, I would be curious what the impedance vs frequency is of your speakers. I did look on your behalf but to no avail. A roller coaster impedance line is going to modulate the power output of a tube amplifier unless the crossover has been designed to be driven with the higher output impedances of a tube amplifier. Just something to be aware of.
just a friendly reminder...Just forget about high power tube stuff for a second. Think of the problems and the costs. I get it you might be rich but you cant pay physics to not apply to you.
Firs of all 150W with a KT150/120. There is not a lot of factory amplifier that properly utilise the tubes let alone kits.
If you want that power level you seriously need to look into the maths and theory behind. No way round arround. Assuming you want to build it. This aint a TDA or a semiconductor jobbie.
I personally think its well worth it to look into it. I myself built the Mullard 5-20W amplifier ground up designed the PCBs and went on to design something proper with KT88 (80or so watts) and its been a year and I am still not done with it. Eventually I want to build with KT150s but those tubes are a challenge. As mentioned before it would be A LOT smarter to go with two monoblocks. The weight will already be monstrous. The power transformer needs to be very beefy to a custom voltage, the output transformer needs to be a custom job aswell, wound to impedances to match the currents those KT150s can deliver at their max allowed voltage. Its not as simple as buy a kit and snot the solderpoint together and youre done. You dont quite realise the design challenges high power vacuum tube amplifier impose. Impracticalities, and the shear ridicilousness (sorry for the spelling) what a 150W KT150 amp would be (and no 150 doesnt equape to 150W). You would need to run a quad of them for each channel. If you got the money I just recommend you ask a credible manufacturer to build something for you to request so you get a properly designed amplifier for what you want. For the cost of course.. Prepare yourself to spend 5K on each channel.
Just to think of the shear current that would run trough the windings of the transformers 4 ohm output makes my spidey senses tingle enough to realise it would be a 25kg output transformer..thats just the OTP..
Firs of all 150W with a KT150/120. There is not a lot of factory amplifier that properly utilise the tubes let alone kits.
If you want that power level you seriously need to look into the maths and theory behind. No way round arround. Assuming you want to build it. This aint a TDA or a semiconductor jobbie.
I personally think its well worth it to look into it. I myself built the Mullard 5-20W amplifier ground up designed the PCBs and went on to design something proper with KT88 (80or so watts) and its been a year and I am still not done with it. Eventually I want to build with KT150s but those tubes are a challenge. As mentioned before it would be A LOT smarter to go with two monoblocks. The weight will already be monstrous. The power transformer needs to be very beefy to a custom voltage, the output transformer needs to be a custom job aswell, wound to impedances to match the currents those KT150s can deliver at their max allowed voltage. Its not as simple as buy a kit and snot the solderpoint together and youre done. You dont quite realise the design challenges high power vacuum tube amplifier impose. Impracticalities, and the shear ridicilousness (sorry for the spelling) what a 150W KT150 amp would be (and no 150 doesnt equape to 150W). You would need to run a quad of them for each channel. If you got the money I just recommend you ask a credible manufacturer to build something for you to request so you get a properly designed amplifier for what you want. For the cost of course.. Prepare yourself to spend 5K on each channel.
Just to think of the shear current that would run trough the windings of the transformers 4 ohm output makes my spidey senses tingle enough to realise it would be a 25kg output transformer..thats just the OTP..
No real need to go to a custom OPT - if the Hammonds are good enough for you. The 1650W will do it. I’m driving mine with 6 6550’s (Tung-sol, the ones that look like the old Sovtek KT88) because they are common tubes, avoiding the long term availability issues of KT150’s or sweep tubes. You could just as easily use EL34’s even, but it would take 8 or 10 of them. That trafo is heavy - bigger than the power transformer in the old PV CS-800. And you can get them at Digikey.
5k a channel? No way. Just the big stuff cost me $1k per channel - you would at LEAST add a zero, or more, to have someone build this for you.
5k a channel? No way. Just the big stuff cost me $1k per channel - you would at LEAST add a zero, or more, to have someone build this for you.
Thanks for your input. The whole KT-thing was just an initial impression I got from the basic research I did as to what tubes were capable of what. I guess you can say I've learned they're not a necessity. I'm not rich by any stretch of the imagination, otherwise I'd have what I want already. I'm looking for a good value in a high power tube amp, hence the search for a good kit. Two monoblocks are exactly what I'm looking at with the M-125's from Bob @ VTA.
I built these, see pics, more here - 120w PP UL monoblocks. 6 EL34's, overwound mains toroid tfmr, 1100u reservoir caps, Hammond 1650TA OP's, protection circuit, etc, etc. They took a long time to build though. Sorry not available as a kit but I can send you the schematic's though.
Andy.
Andy.
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Maybe you should look at bass head kits. If you are lucky they will also be suitable for hifi
Amp-Kit Plexi 150W Bass Guitar
Amp-Kit Plexi 150W Bass Guitar
HiFi is not the OPs objective.
Don't forget to budget for a room with crap acoustics and invite lots of sweaty friends around to listen.
On a serious note, please take care of your hearing.
I am glad you mentioned that Russc that is something I advised many people to watch out for on a very well known UK public help website .
I have all the American data on hearing loss due to insanely loud movies to which very many of the UK public complained about vigorously .
Once those nerves are dead --that's it !
Ear bleeds watching movies and the movie theater refusing to tone down the racket .
It takes many years to feel the full effect of this --does anybody fancy having a hole drilled in your skull and wires attached directly to your brain ?
Check out the number of US children with hearing aids.
I have all the American data on hearing loss due to insanely loud movies to which very many of the UK public complained about vigorously .
Once those nerves are dead --that's it !
Ear bleeds watching movies and the movie theater refusing to tone down the racket .
It takes many years to feel the full effect of this --does anybody fancy having a hole drilled in your skull and wires attached directly to your brain ?
Check out the number of US children with hearing aids.
Thanks for your input Andy, but the M-125s are available as a kit, so it wouldn't make sense going this route.
You can write to them and ask. I know Marshall have som guitar power amps, that are good for hifi as well.
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So I've decided to save up for a pair of those M-125 monoblocks with the KT120's. Thank you for the suggestion. Bob @ VT Audio responds to email fast and is very helpful.
In the mean time, just to get my beak wet, I purchased a cheapie China tube amp from HiFi Exquis - Oldchen K1KT88. Right now it is powering my Legacy Studio HD's in my garage workshop. This amp will eventually be transferred to my office at work after my vacation is over.
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