1.5W+1.5W 單端無輸出牛膽後級

期待已久的套件，卒之可以開工...

可放上他的电路图来看看吗？？

Hi WINDWSS,

上电路图要先找個 scanner 至得...

AP,

可以用 Digital Camera 試一吓, 未必唔得.

我很多时候也是用digital camera的！

Dear CAT & WIND,

相已影好，但恐防 post 在此有版權問題。不如你地 send 個 email address 比我，我 email 給你們好嗎?

Andy

Is this the Single-Ended OTL Amplifier by www.transcendentsound.com?
Please write up some reviews.
I wanna order one too.

Hi Bong,

Yes, it is from Transcendent Sound. The designer (Bruce) always emphasis on good sounds by smart circuit design rather than expensive components so you should expect the kit contains only cheapy components. It is up and running and already sounds good with original components on my 100dB speakers. I cannot compare it with the ordinary tube amp with OPT as this is the first tube power amp I ever built. Also I'm working on replacing components and converting into point-to-point connections. Will post more photos on that later. Thanks.

Andy

Hi Bong,

I have finally modified the whole SEOTL now! It, as mentioned by alfcat, does not sound like a tube amp. However it still sounds pretty good. And after the modifications, the music is more transparent and detailed. I didn't use vintage components, paper tube caps as advised by some experts, to make it sounds more like a tube amp. Rather I would like to let it sound fast as to the nature of OTL tube amp. My next project is to build a 2A3, like alfcat's, to get the warm tube sounds.

Below are some photos for your reference.

Wow! Wow!! U must spent a lot of money on this OTL amp. It looks like you have replaced all the resistors and caps.
How does it sound?


Bong

Hi Bong,

I guess I spent another HK$7,000 for the upgrade! Actually I replaced everything except the 4 B+ caps in the middle. It sounds fast by nature and more transparent, airy and detailed after the upgrade. This is based on the comparison to my previously used solid state amp only because this is my first tube power amp.

Dear AP,

Nice work! You indeed invested a lot in this one.

Your amp should sound OPEN and AIRY as you used the Copper Tube caps. The BASS should be much more punchy and solid than before as well.

Is that how you feel about it now?

CAT

Dear Cat,

It costed me HK$17,000+ totally and it worths more than a very high-end 2A3! Nevertheless this is my first tube power amp I ever built and I just want to make it "looks" and "sounds" perfect before I proceed to the next 2A3 project.

Yes it sounds open and airy but the bass is not that "punchy", perhaps it still need more time to burn-in. I've just finished the upgrade last week!

Happy DIY,
Andy

Yes, the Copper Tube Jensens need around 200 hours to fully run in.

But you SHOULD to able to tell the difference once you replace them with the old stuffs.

So which 2A3 you want to build? PP or SE?

CAT

Dear AP,

You want to take mine? Ha.ha.. I can sell you at cost only.

Thinking of building a 300B ...

CAT

Dear Cat,

Surely SE! I am thinking of a kit from Sound Explorer using Jensen silver wires for all internal wirings! BTW, are you using RCA 2A3? Did you get them from eBay?

Andy

Yes, I am using RCAs.

I have VT-95 Black Plates, USN CRC ones as well. All Black Plates.

I also have Type 45 from various manufacturers.

Yes, I got all the tubes from eBay. Just don't be too anxious to get them. You have to wait for the opportunity. I test the tubes after they arrive with my own tester.

Hey, I am serious. I have thought of selling mine. Any interest?

CAT

[quote:07c9f0fa9d="alfcat"]Hey, I am serious. I have thought of selling mine. Any interest?[/quote]
Dear Cat,

But I really want to build one by myself   Actually your OPT (XE-20S) and Jensen caps can be reused for 300B.

Andy

Dear Andy,

Yeah, I know I can use the XE-20S and the Jensens back. If nobody wants the 2A3, I may as well keep it to do the AB comparison with the 300B I am going to build.

I went to brother Yuen's place today and order the major parts like the Case, OPTs, PT, etc. and asked them to drill the holes for me as well. However, there is no power transformer available and I have to wait 2 weeks. Nice ... I can get my toys after my pay day.

:

What is brother Yuen's place?
Parts store?

After I finish the Sun 2A3, I wanna build a 300B too!
Any ideas?
AudioNote Kit 1 300B?
AudioNote Interstage 300B?
Sun Audio 300B?
I have found both of the AN 300B schematic on line.


Also have you guys tried this Paper In oil cap from Russia.
0,22uF 1000V PIO capacitors K40y-9. I found some good review online

Bong

[quote:0d36e2ef0e="alfcat"]Dear Andy,

Yeah, I know I can use the XE-20S and the Jensens back. If nobody wants the 2A3, I may as well keep it to do the AB comparison with the 300B I am going to build.

I went to brother Yuen's place today and order the major parts like the Case, OPTs, PT, etc. and asked them to drill the holes for me as well. However, there is no power transformer available and I have to wait 2 weeks. Nice ... I can get my toys after my pay day.

:[/quote]
Dear Cat,

So did you find your 2A3 not powerful enough? What is the sensitivity of your speakers? If you are going to sell it with the tubes, I can think about it ...... I promise not to dismantle the parts and keep it for comparison
There is an all-silver-wired 2A3 by brother Yuen I mentioned above and that is what I am planning to build, but with a pure copper case :mrgreen:

Andy

[quote:d9fe3c654b="BongCalifornia"]What is brother Yuen's place?
Parts store?

After I finish the Sun 2A3, I wanna build a 300B too!
Any ideas?
AudioNote Kit 1 300B?
AudioNote Interstage 300B?
Sun Audio 300B?
I have found both of the AN 300B schematic on line.


Also have you guys tried this Paper In oil cap from Russia.
0,22uF 1000V PIO capacitors K40y-9. I found some good review online

Bong[/quote]
Dear Bong,

Yes, brother Yuen's place is called "Sound Explorer", a good DIY components store in Yau Ma Tei, and is very popular among tube amp DIYERs.

No, I didn't try those Russia caps before. Jensen's paper in oil caps are good enough for me

Andy

cat sir,

Which circuit of 300B are you planning to make?


anybody here had try make 2A3 with audionote kit 1 300b(circuit)? (driver using SRPP circuit)

Dear AP,

Well, it is not the 2A3 not powerful enough. I think the circuit I use has a lower gain than the original 6SN7 circuit. The Amp does sound good, even better than the Sun Audio 2A3 as told by some of my friends.

I am using a pair of Castle Conway 3 floor standing speakers. Their sensitivity is 91db at 1m.

On second thought, the tubes are still available at ebay but the Black Gate 100uf + 100uf .... if I sell the amp to you, I don't know where I can find another one of this ... ha... ha...

Have we met before? Maybe I take the amp to your place for an audition before we decide on anything, ha..ha.

CAT

WINDWSS,

I cannot post the 300B circuit here as the owner doesn't want it published openly. If you really need it, I can email it to you.

No, I haven't try the Audio Note Kit one circuit and I don't know anyone who had tried that circuit as well.

I got a friend who purchased a AN 300B two months ago. I bumped into him two days ago and asked him about the amp. Unfortunately, he has got much time to properly set it up yet. Else, I would like to go down to his place for an audition.

CAT

Sorry, typo.

My frined "hasn't" go enough time to set up his 300B properly.

Dear AP,

Do you want me to take the 2A3 to your place for a listening test?

CAT

[quote:4dcecad2e0="alfcat"]Dear AP,

Do you want me to take the 2A3 to your place for a listening test?

CAT[/quote]
Dear Cat,

You are welcome to take your 2A3 to my home for an audition   I'm living in Kowloon City but my listening environment is not good enough. Hope this won't affect the performance of your 2A3 ops:

I'm free on this Saturday afternoon and next Monday morning. Please advise if they fit your schedule.

Andy

Dear AP,

Please check PM

CAT

[quote:a7a6a1cbfa="alfcat"]Dear AP,

Please check PM

CAT[/quote]
Dear Cat,

Couldn't send/receive PM here. Please use PM in R33

Andy

Oh, please PM me in R33 then. I can't find yours, ha.ha..

You can locate me in PASS DIY under 影音天地

Thank you