[Niteshade]

The Antique Sound Lab KI15 is a mystery to me. There is nothing written about it, including specifications! It was made in 2000 and that's all I know.

If you have one, could you fill me in on the specifications and how it sounds? This has to be one of the rarest amps I know of. Reason I'm asking is because I have one and would like the spec's and your opinions of it.

Any information would be greatly appreciated!

[Niteshade]

I found out she's supposed to put out 22 watts/channel. The iron supports that claim, but the driver circuit doesn't seem to be up to that claim. I'm measuring around 10-15 MAX.

Some interesting data:
1. Common cathode output stage. (6AS7 anodes connected directly to B+)
2. 290v+ on plates (too much)
3. MAX -140v bias system (too low for that B+)

There are other issues- but this is a start. I have it sounding **very** good after modding the power supply and have the tubes happily at 255v w/ a bias of -135.

More info later. As stated before, I'd like to hear what owners of this interesting amp have to say about  it's performance.

[FullRangeMan]

Interesting  infos,  Thanks for share this report. Looks this 6AS7 tubes will have short life.
And the others ASL amps may use this procedure of force pressure on the output tubes, as the top of the ASL line, the Cadenza DT is rated 60W with only two 845 tubes.
Do you think 60W is too much for two 845?

[Niteshade]

The 6AS7 is a hearty tube when used properly. I modified the KI15's power supply to provide 255v and they tubes are happy now- they will last a long time.

845 tubes are designed for high power RF amplifiers and can put out substantially more than what most audio manufacturers ask of them. Sixty watts is not even turned on to these giants. A close cousin is the 572B tube. 500 watts can be obtained from these in a push-pull circuit. Everything is high voltage & high impedance with large RF tubes making them expensive to build around. I still like them! Very little has been invested into them regarding audio equipment- I'd like to see that change since they are VERY good at handling high power.

Interesting  infos,  Thanks for share this report. Looks this 6AS7 tubes will have short life.
And the others ASL amps may use this procedure of force pressure on the output tubes, as the top of the ASL line, the Cadenza DT is rated 60W with only two 845 tubes.
Do you think 60W is too much for two 845?

[FullRangeMan]

Thanks for your input Blair.   I was think the 845 are rated at 22W as I see on some specs charts of NOS 845 tunes.
The new KR-845 (Kron site) is reted only 20W to 26W and should cost some dollars.   I love the 845 and the 211, unhappily the omnipresent 6550/KT88 have no effect on my taste.
Regards

[Niteshade]

90% of what an amp sounds like is derived from the circuit. You shouldn't think in terms of liking or disliking a specific tube in terms of sonics. I have listened to just about every tube that can be used in an amp including some unconventional ones and found they all can sound exceptionally good.

Think of tubes/parts/etc... like cooking ingredients. Take the same set of ingredients to three different cooks and one will make a meal you'll remember for the rest of your life and another could trigger your gag reflex.

Note: Tube types can have signatures. These can be worked with either to an advantage or disadvantage. Most of the time it's best not to lean into a signature tone quality- and instead go for neutrality.

[FullRangeMan]

This is a important info to consider about any tube amp. 
Do you know if the 211/845 have any problem or unusual feature ?

[Niteshade]

From what I have observed so far, these tubes lean towards having a rolled off top end and have a warm midrange. I have not made a high-powered triode based amp yet so I don't know if there are ways to change these signatures. I don't believe these traits are overbearing at all and it could be partly due to the circuit involved.

This is a important info to consider about any tube amp. 
Do you know if the 211/845 have any problem or unusual feature ?

Are there are ASL KI15 owners around? I can't believe nobody has had one or has never listened to one someplace else. Could they be that obscure?

[FullRangeMan]

Thankyou for sharing yours impressions.  As there is two types of the KI-15 (the 6AS7 and the 6C33), may be  that the KI-15 FOX (6C33) is more commom and your 6AS7 type could be more rare.
Just a idea.
http://www.audiocircuit.com/index.php?c=ANP&m=KI-15-6-AS-7     This is a so so link, no much info

[Niteshade]

Thanks for the link- nobody uploaded any data there but that's par for the course for this amp. 


The KI15 6AS7 is clearly a very,very rare bird. I've been enjoying it in the shop and like it more and more! It's running great after the mods and will accept any 6AS7/6080 tube without fear of damaging the amp or tubes. 

Does anybody have the 6C33C version of this amp? I've seen it and it looks pretty neat.

[Bill Baker]

Hello Blair,
 The 6C33 amp is a different unit altogether. The integrated version is rated at 22 watts and the mono blocs at 60 watts. I have heard both and did a lot of work on the mono blocs.

 The KI 15 was not offered in the US if I recall. If it was, it was for a very limited time frame. The original ASL gear was derived from AS-USA (Antique Sound - USA) who offered many kits as well as finished products and were located in Washington for a short period of time.

 ASL is located in China but also do OEM work for Divergent Technoligies. These products can be identified by the "DT" after the model.

 I use to have almost all the ASL schematics but lost many for the older units during the flood of 2006.

 Your amp is not rear but most likely not too many made it into the USA. These older designs had a lot of potential but as you have noticed, needed a lot of modification (mostly the power supply) before sounding their best.

 The transformers always seemed to be of decent quality.

[FullRangeMan]

Thanks for the link- nobody uploaded any data there but that's par for the course for this amp. 
The KI15 6AS7 is clearly a very,very rare bird. I've been enjoying it in the shop and like it more and more! It's running great after the mods and will accept any 6AS7/6080 tube without fear of damaging the amp or tubes. 
Does anybody have the 6C33C version of this amp? I've seen it and it looks pretty neat.

The KI-22 FOX have some good press:
http://www.enjoythemusic.com/Magazine/equipment/0101/aslki22fox.htm
http://www.blackdahlia.com/tipindex/ASLamp/tip_23.htm
Then the 6AS7 version should sound good too.

[Niteshade]

Thanks for all the information! I'd like to try the 6C33C out sometime- it looks like a fantastic tube. Not too many are using it now- it must have something to do with the popularity of 300B's & 2A3's.

[FullRangeMan]

Thanks for all the information! I'd like to try the 6C33C out sometime- it looks like a fantastic tube. Not too many are using it now- it must have something to do with the popularity of 300B's & 2A3's.

Good news !!   Iam a 6C33 fan to OTL and OTCoupled, and they are really very inexpensive, today they are under 10 dollars each  at   http://www.gstube.com/catalog/1/  and Mr.Anton service is friendly, payment is through PayPal.
If you try something, please send me a PM about the results, as Iam very interested in 6C33 amps.
Cheers

P.S.: Errata: the payment is by MooneyBookers or WesternUnion, not PayPal.  MooneyBookers has lower tax rates in 2008.