Hi all.
In these days of 'lots of free time', I purchased what I believe are the last two available Tubedepot K11G monobloc kits. They are, for all I know, an S-5 Electronics design. I call them my 300 V mousetraps, since I do not have yet an enclosure over them...
I built them exactly as per instructions (with the optional C8 electrolytic), as I wanted first to hear what they sounded. They are rally easy to build, I did both of them in one sitting with no testing along the way (I do have a bit of experience building electronics).
Well, I hooked them up to 'good' speakers (old Madisound Recession II Buster kits) and fed them from my preamp out before turning them on. Then I flicked the inline switches and turned the volumes pots fully on.
I thought, since I didn't test anything while building, that I must have made a mistake somwehere: with my ears right up to the speakers, I heard absolutely nothing! No 60 hz hum, no 120 Hz buzz, nothing!
Still I dropped the stylus on the record, and wow! A nice 8 W of music, with reasonable bass.
They still are only 8 W, i.e. 3-4 W of clean power, but they sound just fine with mid-efficiency speakers in a large living room. The power transformer runs hot, but the output transformer remains cold, go figure.
I am quite happy with these and I am considering their bigger and more advanced brothers, the 16LS or 16LM (to make it easier on the power supply).
Anyway, I thought I'd share this... Cheers!
--Christian
In these days of 'lots of free time', I purchased what I believe are the last two available Tubedepot K11G monobloc kits. They are, for all I know, an S-5 Electronics design. I call them my 300 V mousetraps, since I do not have yet an enclosure over them...
I built them exactly as per instructions (with the optional C8 electrolytic), as I wanted first to hear what they sounded. They are rally easy to build, I did both of them in one sitting with no testing along the way (I do have a bit of experience building electronics).
Well, I hooked them up to 'good' speakers (old Madisound Recession II Buster kits) and fed them from my preamp out before turning them on. Then I flicked the inline switches and turned the volumes pots fully on.
I thought, since I didn't test anything while building, that I must have made a mistake somwehere: with my ears right up to the speakers, I heard absolutely nothing! No 60 hz hum, no 120 Hz buzz, nothing!
Still I dropped the stylus on the record, and wow! A nice 8 W of music, with reasonable bass.
They still are only 8 W, i.e. 3-4 W of clean power, but they sound just fine with mid-efficiency speakers in a large living room. The power transformer runs hot, but the output transformer remains cold, go figure.
I am quite happy with these and I am considering their bigger and more advanced brothers, the 16LS or 16LM (to make it easier on the power supply).
Anyway, I thought I'd share this... Cheers!
--Christian
Attachments
Christian, i built a K12 many years ago and added several mods suggeated by Bruce Heron, a member this forum. It sounded pretty good even with the modest specs. BillPennington
Hi, Wow, talk about a shout from the past. I did indeed make a lot of mods to these types of amps (so did lots of other folks). I believe it was about 11 years ago. For what they were designed to do and the cost they are not too bad. I personally found that the sound was not as good as I thought a tube amp should be. So, I did a lot of mods to it. The end result was better, but beware the cost of the mods can easily exceed the price of the amps. The mods are covered well in a project write up on another site (diyaudioprojects.com). Since then I completely rebuilt the amps in accordance with my own designs for other power amps. They are much improved. About the only things left of the S-5s are the tubes and PCB. I did get a case for mine (a K-12) and that really is nice. The amps make a fairly good introduction to tubes and a great place to learn as well. Have fun.
No figuring. The output transformer should remain cool. If it gets hot, something is wrong.
Attachments
The PT does real work all the time.
The OT does NO real work at idle. Even pushing 5W peaks is only a half-watt average audio power.
Thanks for the replies. It's just that the power transformer is quite large, I was surprised at how hot it ran at idle. I have other tube amps and their power transformers are cooler! Cheers all.
--Christian
--Christian