Review of New S-5 K-16LS Kit

[fenpark15]

After building, troubleshooting (thanks to those who helped) and burning in of the new s-5 16 Wpc stereo amplifier kit, I want to share my thoughts for anyone who may be interested. The kit is straightforward and easy to build and comes with pretty good instructions. I decided I wanted to hear its sound mostly stock before I upgraded poly film capacitors or anything like that. The modifications I did make include:
-metal chassis
-3 prong power supply grounded to the chassis with toggle switch
-AC cooling fan
-Bigger filter caps (220 uF, 220 uF, 100 uF instead of 220, 100, 22)
-270K bleeder resistors on filter caps
-bypassed capacitors on RCA inputs with wire
-Gold-plated chassis mount RCAs and binding posts

I included the fan because I'd heard that other s-5 power transformers got pretty hot. I think this PT is a beefier one than with the k-12 and the fan is probably not necessary.
First impressions of the sound are that it has a noticeably different tone than my several run-of-the-mill solid state amplifiers. Sound is warmer and more vibrant. With the input source paused, there is very little noise and no noticeable hum even at full volume. I didn't even add any snubber capacitors yet, but I'm already satisfied. I did attach the tone control option from s-5, which I'm glad I did, as different styles of music and different recordings require some adjustment to sound good. With the proper adjustment of the tone controls, bass, treble and mid are all satisfactory. With my Klipsch Heresys, full volume exceeds comfortable listening level and bass is ample.
Keep in mind this is my first experience with tube audio and I have never heard other tube amplifiers for comparisson. Thus, I'm probably not the best person to review an amplifier for tube enthusiasts. But, I would say that, at a total investment of under $400, the amp sounds noticeably better than the $350 solid-state amplifier it is replacing.

[fenpark15]

and a picture of the outside

[gmilitano]

Thanks for the info.

Do you have a scope?

[jduffy]

Nice job friend! From all of the tweaks that I've seen on various websites, you can keep playing with this for quite a while! That's a great aspect about kits that have been seriously exploited by the tweakers.

[fenpark15]

Unfortunately I don't have a scope. I'm a physics student, so there's a chance I could take it in to one of the labs and test it there. But, I don't have dummy loads either yet.

[Sal Brisindi]

Looks nice but to tell you the truth and not to reign in on your parade, when I hear someone spending $400 on an amp like that why not buy a used Dynaco ST-70? Trust me, you can find good used ST-70 for under $400.

Regards,
Sal Brisindi

[123rmp]

Fenpark15 -

I would like to exchange emials with you regarding your upgrades and overall experience with the 16 LS kit, but as a newbie who is "under moderation" I cannot email you from the forum.

Is it possible for you to email me via the forum?

Thx

[dubdub]

its good to see a review of tis kit-there was another one on http://diyaudioprojects.com/, but that was mainly about the results of a scope test- a description of the sound quality would of been a plus.

diyaudioprojects is a great resource (and good reading), to be fair they did ask for experiences with this kit to be shared and compared.

however a 2nd opinion was needed in my view as I think the kit is good value!

[gmilitano]

Here are Bruce's measurements of the S-5 Electronics K-8LS Tube Amp Kit. As far as we are aware, these are the only measurements of the new kits right now. As you mention, it is important not to pass judgment based on just one set of measurements.

We have had a small handful of subjective emails, some good and some bad. Here is a link to some subjective comments about the K-8LS kit:

http://www.diyaudio.com/forums/showt...09#post1310309

These comments seem to confirm the poor response in the bass region.

Originally posted by dubdub
its good to see a review of tis kit-there was another one on http://diyaudioprojects.com/, but that was mainly about the results of a scope test- a description of the sound quality would of been a plus.

diyaudioprojects is a great resource (and good reading), to be fair they did ask for experiences with this kit to be shared and compared.

however a 2nd opinion was needed in my view as I think the kit is good value!

[Ben10]

This will be my first build. Wondering if anyone has any advice?

I am lucky enough to have access to a machine shop so I'm going to make a chasis out of aluminium.

I was thinking of making some transformer covers too. I know this is very extravagant for a cheap kit but I have access to free metal so I figured why not...

I would be interested to hear peoples ideas on chasis design.

I am going to use some decent RCA's and binding posts.

I was thinking of using chasis mount valve sockets then wiring these to the PCB. Can anyone foresee any problems with this?

Also any other weird and wonderful ideas... Throw them my way.

I want to make the most extravagant ridiculous cheap *** amp I can.