Would an s5 K-12M kit suffice?

[edjosh23]

I'm a noob to diy audio, I built my first Gainclone a few months ago and a pair of speakers using the WR125s. I want to build a tube amp, and have done a TON of searching. I've read a lot of you all's suggestions, and the K-12M seems like it might be the best for my budget. I'm willing to spend about $250, and I think thats about how much I'll end up spending after the modification

The Wr125s are only 85.6db efficient. Will the 8 watts be enough? I know very little about tubes, and have only listened to them a few times. A friend of mine's dad is a guitar player and has a recording studio and he loves tubes, he says he likes it better when the tubes are hot, is this true with music listening, and not just guitar? Would the amp have to run hot to power the speakers at normal listening level, or maybe a little above normal listening volume? I'm 17, and am about 10 feet away from my speakers when listening and sometimes like to turn up the volume a little high.

Do you all think this is a good kit for me?
I'm willing to MAYBE take up to $300 but I would prefer not to.

Thanks,

Josh

[edjosh23]

I talked to timn8tter about the project, whom also built one, he said it would be a great project for me and recomended me doing the mods. Although he did not comment on the WR125s.

Can anyone tell me if the K-12M will be a sufficient power source for the WR125s.

Thanks,

Josh

[gmilitano]

I recently built the S-5 K-12M Tube Amp. Those speakers seem a little low on efficiency. There are some who are happy with 87dB speakers, but I would reccomend something closer to 90dB.

Visit my website for more info about the amp.

Cheers,
Gio.

[edjosh23]

gmilitano,

Timn8ter told me about your site, I read it earlier today actually.

I was talking to Planet10 earlier today and he recomended the K-502 due to different tubes which he says are more well known. In the furture I'll build some new speakers, but I recently built the WR125s and wanted to try them out with tubes. I'd really like to do a tube project, but I just don't know which will work best and sounds the best. Planet10 also recommended the ASL Wave 8s which look very nice, but I don't have a preamp, but I was thinking maybe combining the two and adding a pot.

gmilitano, I have a pair of B&W 602's that are 91db, those would work well, but personally the wr125s sound better. Could I listen to the WR125s and the 8watt tube atleast at normal listening volume?

Thanks,

Josh

[Sherman]

Originally posted by edjosh23
...The Wr125s are only 85.6db efficient. Will the 8 watts be enough?...
Thanks,

Josh

Josh,
I also built one of these amps and did the modifications on Voltsecond's site. (Many of them were done already on the version of the board I got, including ceramic tube sockets.)

When finished I used it for a couple of months with a pair of Advent/1 speakers. I believe the Advents are about 87-89db/w/1M. If your room is smaller or you don't plan on listening at ear-bleeding volume 8W might be enough for 85dB speakers. Meaning if you listen to acoustic music, chamber music, most jazz etc. you should be OK. But... if you like to occasionally blast head-banging music you'll probably be disappointed.

Remember that 3dB increased efficiency in your speakers is almost like doubling your amp's power. I would recommend building the amp as a first tube project and then build some efficient speakers to go with it later on.

[planet10]

Originally posted by edjosh23
Wr125s are only 85.6db efficient. Will the 8 watts be enough?

At the rated power this gives you 94.6 dB at 1 m at clipping. tube amps typically compress instead of hard clip so there might be a bit more headroom than that.

That is fairly loud... it now depends on how loud you listen, how compressed the music you listen to is, and how big your room is.

It is a very good starter kit... add a copy of Morgan Jones "Valve Amplifiers" and away you go on a journey into tubedom.

dave

[planet10]

All 4 amps mentioned (there are 2 versions of the antique electronic supply amp) use tubes with a triode section & pentode section. They use one of the triode sections as a gain stage, the other as a concertina phase splitter, and then the PP output stage. This is a classic design.

I have a couple old Viking amps (one 6BM8s, the other ECL86) that are the same topology. They are going to be resurrected but i will wire the triodes in a differential phase splitter with a CCS on the cathodes.

Something like this http://www.diyaudio.com/forums/showt...739#post552739

dave

[planet10]

And a good place to start learning:

On Line Tube Learning for newbies....

dave

[planet10]

and Volt-second's tweak page:

http://www.siteswithstyle.com/VoltSe...Push_Pull.html

most of those tweaks probably can be tried on other amps...

dave

[leadbelly]

Dave,

I was reading through your posts on these amps. So if I have it right, the S5 K-12M uses 11MS8 tubes, as does the AES K-501 monoblock, and the AES K-502 uses the 11BM8. These tubes appear very similar, 1 triode + 1 pentode.
You probably know what I am going to ask: what's the Tim-the-Toolman bigger tube to cram in there to hot-rod it? Assuming of course one can live with swapping things around for heater voltage, etc.