my 6922 / E88CC preamp

[alexw88]

Finished with my simple E88CC preamp, tested with JAN Philips, Siemens and Telefunken tubes. They do measure differently, with the Siemens having the lowest distortion.

I really love the E88CC 😀 Just want to share my work :

http://shine7.com/audio/6922_pre.htm

 

[SY]

Very neat and clean construction! Well done.

 

[barossi]

Hi,

very nice indeed!
Where did you buy the PCB's?

KR

Hauke

 

[SigloOne]

Where did you get the chassis/case? it's got a nice look.

 

[alexw88]

Thanks!

PCB is from a local DIY supply store in HK.

Chassis is from a Taiwan DIY site http://www.my3c.net/product/default.asp?gid=116

I think it would be difficult to order from them without knowing Chinese. You may try to email them : service@my3c.net

 

[lineup]

6922 E88CC 6DJ8

.
I like this one.
If I will make me one 250 Volt DC supply I try this!
As I recall these tubes also need heater Voltage/current
at like 6.0 - 6.3 Volt ...... DC or AC.
Is this correct?

Making one 250 VDC supply is not as difficult as we think.
It is most about find a suitable transformer
that outputs like 180 VAC .. or 2 x 90 VAC.

These can be found at almost any electronics internet shop.
At least I can get 230 VAC in ... 2 x 115 VAC out Trafo.
Need not be too big as the Current involved is not very high .....

I attach your schematic, if you do not mind.
I got it from your website:
http://shine7.com/audio/6922_pre.htm

regards 🙂 lineup

 

[poynton]

PCB is from a local DIY supply store in HK.

Buy some and put them on the market place at a reasonable cost.
There would be a lot of interest.
I would have a couple!!

Andy

 

[SY]

I've seen those boards being sold already. Chinese vendor that people thought well of. Wish I could remember who...

 

[ErikdeBest]

SY and his memory 😉

quoting from the thread
http://www.diyaudio.com/forums/showthread.php?s=&threadid=115941

SY, if you ever make it to HongKong you have to visit the store where I saw those solder stands. Bush Electronic Supply, in an alley behind a pretty big street in Hong Kong central or the Centre. You enter the alley, then walk up some steps and you enter the shop. Amazing, the contrast. http://hktubeaudio.homestead.com/files/Central_tube.htm Daan

similar PCB is available on E-Scam http://cgi.ebay.com/MULTI-PURPOSE-T...7QQcmdZViewItem not associated with the seller.

a more up to date link
http://cgi.ebay.com/MULTI-PURPOSE-T...VQQcmdZViewItemQQ_trksidZp1638Q2em118Q2el1247

Since there are interest in these, here is a close up photo : I bought them from : Sound Explorer Company 凱韻音响電子公司 Flat A, 7/F., Hamilton Comm. Bldg., 558-560 Nathan Road, Kowloon Phone : +852 2332 1821 If you have a chance to pass by HK, buy some

 

[alexw88]

Don't understand why there is so much interest for that PCB, is that because of the color and look?

How about paint your standard prototype board for the look and feel you like? Here is what I did :

Noticed the top small prototype PCB was originally standard green color, I painted it black to match the other PCB.

 

[ErikdeBest]

Hi Alex

I do not think that the interest on the PCB is due to the looks, but rather for its versatility (or isn't that the reason you choose it?).

Erik

 

[alexw88]

Erik, yes, the original idea I use this PCB with the copper stand is that I can change resistors easily to try different loadline design.

Also, the same PCB wiring (almost) is used for my 12ax7, 12au7 and this 6922 preamp, just change the resistors and I can try new tubes.

Besides, I do think the blue color is quite nice.

 

[Karsten Sømand]

Hi SY and other fellow DIY´ers.

Have a look at this link. The PCB looks pretty much the same style as the one Alex uses (maybe not 100 % identical).

I don´t know how interesting this PCB is when you look at the price of 27 $ US.

http://www.kitsparts.com/shop/index.php?main_page=product_info&products_id=122

Kind regards

Karsten

 

[ErikdeBest]

Hi Karsten

27US$ is a lot of money, from the e-bay link you can get them for about half that, excluding shipping costs.

Eri

 

[nitrate]

Excellent little project. The 6922 is one of my fave tubes. It has a lot of versitility being of quite low distortion, able to work at low voltages and having quite high Mu and current handling. People usally slate this tube and dismiss it for audio use but i think its O.K

Leigh

 

[regal]

I had a similiar preamp, I found that there was better sound by not using the cathode follower. If your amp is 50k + ohm input impedance you may want to try this.

 

[lineup]

Have a look at this link. The PCB looks pretty much the same style as the one Alex uses (maybe not 100 % identical).
I don´t know how interesting this PCB is when you look at the price of 27 $ US.
http://www.kitsparts.com/shop/index.php?main_page=product_info&products_id=122

Have a look also at the other Tube pcb stuff from www.kitsparts.com
like for example
Modified ARC Audio Pre-Amplifier Tube Full Parts Board
... of course it costs money: $117

An externally hosted image should be here but it was not working when we last tested it.

 

[lineup]

Here is the SCHEMATIC
http://www.kitsparts.com/shop/download/audio/schematic_pdf/ar10.pdf
for that
Modified ARC Audio Pre-Amplifier Tube Full Parts Board
... of course it costs money: $117
and here is the page:
http://www.kitsparts.com/shop/index.php?main_page=product_info&products_id=119

 

[barossi]

Hi,

o.k. one could buy the PCB @ ebay, but what about the copper stands?

Kind Regards

Hauke

 

[lineup]

Copper Stands

yes, would be nice to find some good buy of those.

But if you have 1-2 mm thick SOLID COPPER WIRE
you can cut those and make your own 'stands'