DIY Single Ended Tube/SS Amplifier Kit - Preliminary Inquiry

[Hiten]

Hi all,
I think I can use low power SET amp for some of my music. Am Looking for some DIY/semi assembled single ended Tube kits or good designs with easily available components. Should be simple to assemble. I understand with quality components they get expensive on logarithmic scale. Don't have any clue how much they cost. So no budget till I find cheapest good design.
Selecting Solid state design is very easy. That will be AmpCamp* by Nelson Pass. But As I have some tubes (ECL82) am leaning towards it more. Can buy new tubes also as nothing is fixed. I also understand safety measures with high voltages involved. I have limited understanding of electronics but I am looking for...

1) Most Important : Good well appreciated simple published circuit design. (Will be joy to start from scratch. Other too can join)
2) Low power 2 to 3 watts is OK.
3) No push pull design.
4) Am Ok with regular normal affordable OT.
5) No expensive tubes. (No 300B though they are V. Good).
6) Amplification stage Tube based but rest of the design SS is perfectly all right.
7) Chinese designs are cheap but doubt their genuine circuit design and components. unless some kind knowledgeable soul guides me to it.
8) P2P will be icing on the cake.

* Can anyone tell how much AmpCamp Amp. Only PCB+Components costs ? (No heatsinks, Connectors, enclosure etc.)

Thanks and regards.

 

[Hari Iyer]

FM Prem forwarded me this link when I was on my project to upgrade my 300B tube amp. Look if this is of any help to your project.
https://www.dhtrob.com/schemas/#*

 

[Hiten]

Thanks for the Link Hari.
Yogibear please do give suggestions/links. As I have already said I can buy new tubes too.
regds.

 

[keith_correa]

https://geardiary.com/2017/12/01/audiophile-budget-fx-audio-tube-01-best-tube-buffer-money/

Maybe this and SS amp of your choice.

 

[Hiten]

Thanks for the link Keith. Amplification by Tube is what I am looking for. Think of it as adding tube flavour to my system. As said in my CNC phono thread. I will be putting it with phono pre which will drive wideband single speaker (Later on). Will be good for some vocal music I guess.
Thx and regds.

 

[Hiten]

Thanks Yogibear. I will go through them.

 

[Hiten]

After searching I think I will start first by practicing before I get on to some mid hifi OK SET amp.
https://www.tubecad.com/2004/blog0005.htm
The third simple schematic above I have most of the parts. (AD712 and LM317) Lets see how this rudimentary circuit sounds. I guess most of the working is hidden in op amp and LM regulator. IF SUCCESSFUL I will try the next tube circuit on same link. which says "World’s Simplest SE Class-A amplifier". I have a feeling probably that circuit has some drawbacks (Probably bandwidth of single tube.?) This will be just practicing before I (may ) dwelve in to some Okayish High Fidelty SET Amp. if not there is always good option of SS AmpCamp Amp.
Regds.

 

[Hari Iyer]

Any progress on this? Curious to know.

 

[Hiten]

Bro, I have shorlisted few schematics for SET AMPs. need to select and search where parts can be obtained. As for AD712-LM317 SET Amp. no progress as my home is being repainted. Also a little bit of procrastination from my side. On the above link Can you tell me the 'adj' pin on LM317 what its about. I guess its is about bias setting but no value has been said. Also resistor marked '1' at bottom has no value or wattages. dont know f it is 1 ohm or 1 K or 1 M ???
Thanks and Regards

 

[Hari Iyer]

@Hiten
As they have not mentioned any thing, it looks like 1 ohm to me. In the +ve cycle it's directly connected. Only -ve cycle has 1 ohm

 

[Hiten]

Thanks very much Hari.

 

[jls001]

Hiten, do check out this thread:

https://www.diyaudio.com/forums/tubes-valves/311212-gold-mine-di-audio-tubes-schematics-japan.html

 

[Hari Iyer]

Hiten, do check out this thread:

https://www.diyaudio.com/forums/tubes-valves/311212-gold-mine-di-audio-tubes-schematics-japan.html

Jousha, its a good link/ find. I checked a couple of 300B schematics. Unfortunately all notes are in Japanese language. If some important notes are missed only by looking at the schematic it could be risky to build imo.

 

[Hiten]

Hiten, do check out this thread:

https://www.diyaudio.com/forums/tubes-valves/311212-gold-mine-di-audio-tubes-schematics-japan.html

Yes joshua. I am following that thread along with some other more recent. As of now I have some links which I will share soon. Simple Single ended triode is challenging (Pushpull have more wide band, linear and power to accomodate various speaker criteria) I understand somewhat limitations of single ended so I have my requirement to that needs i.e. limited wideband, low power, No expensive tubes, and somewhat (will do) transformers.
Regards

 

[Hari Iyer]

SE tubes especially the 300Bs are super expensive. Also the OPT is very fussy to work with. If these two things are sorted out then SE should be great. 2A3 tubes are relatively cheaper compared to the 300Bs.
If going SE, select the speakers first before you built the amp..

 

[jls001]

If going SE, select the speakers first before you built the amp..

Good point!

 

[Hiten]

Bros,
Kindly read my first post point 5, I am aware of very good 300B Tube and have eliminated it from my basic needs.
Am also aware for low power, sensitivity of speakers plays important role.
Warm regards.

 

[Hiten]

Posting some of the Single ended, low power and workable amp design collected from Internet. Anyone looking for simple SET tube amps then these will probably your entry/introduction to it. They have very low parts count, no PCBs required. Some have NFB some do not. I would prefer NFB with low output. All require High Sensitivity Speaker Driver though.

1) The Mini-Fi : Couple of clean watts using ECL86 Tube. Article is well documented and parts are affordable .
Link
The Article is on page number 82 of the Magazine.

2) RH84 Rev. 2 : This came too often while searching the net. Looks like well made it says about 4 to 5 watts so speaker driver choices have little bit more options.
Link

3) Shinichi Kamijo 6BM8 : Japanese never abandoned tube amplification. They are in forefront of designs, Kits and new tubes etc. This design is from Shinichi Kamijo.
Link
Another well documented build.

4) EL84 : This is already posted and is very good design.
Link

5) Mullard 3-3 Classic : This is well regards vintage design. You can discard the tonecontrols.
Link
Very well documented and linear design. A British Classic.

6) Menno van der Veen (The Maurits) : This was recommended by ThorstenL of DiyAudio in some thread
Link
This is probably the most thought after design by the Author who is valve expert.

Other too simple (Nitin Willimas single tube amplifier); AND a little complex but Well experienced Designer Amps are Jim Mcshane El Cheapo, Fred Nachbaur SET AMP, Diyaudioproject's 6T9 SET and Diyaudioproject's Ultralinear 6T9 etc. Do search for them if anyone interested. Some links dont work so have not posted.

Hope this helps others who may want to build. I will have a look at how much above build/s cost and availability of Tubes and output transformer. I have a friend who visits USA often so probably output transformer and tubes will be bought by him. Lets see.

Disclaimer : These are not at all high quality, Proper, High Fidelity SET Amps. Those require 'Proper' Audio quality low distortion Driver and Power Tubes and High quality output transformer.

Regards

 

[shanindia]

Hi,

Was going to post a new thread on this, I came across Elekit TU-8100 PCL-86 set amp. Looks like very good quality kit. Works on 12v power supply, 2w output. Has anyone looked into it, how is it in terms of cost to performance? Atleast safety wise it seems to be good (12v supply only) and small size as well.

~Shanindia

 

[Hiten]

Yes I have seen that kit. It sells for around 20,000 add to that shipping. I am not technically knowledgeable and that kit looks elaborate implementation with safety priority. SMPS and other electronic implementations takes the fun out of simple single ended designs. But overall looks like good. I will trust japanese to make well made product.
As for performance distortion figures on that one looks more compared to schematics I have posted. But hey ! people love distortion hee hee. Also thanks for sharing. : )
best regards.