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Civilian 6n2+fu32 tube headphone amp

post #1 of 56
Thread Starter 

Civilian 6n2+fu32 tube headphone amp

 

 

 

 

 

Bought this amplfier (110v version) recently from a Singapore reseller. Arrived in under 10 days in perfect condition. Prompt service & answer emails but no tracking.Total cost including shipping, paypal, $226.00. One of the chinese fu32 tubes failed after one session, but no loss as always replace the chinese stock with NOS anyway.

Biffed out all the chinese tubes & replaced with NOS. I love the 1940's tubes & after researching found that the 832A is a direct replacement for the fu32. These are way cheap & plentiful to buy & knock the socks off any later 9 pin miniature set ups (IMO), that I have tried. Same cannot be said for the 6AX7 (replacement for the 6N2) which is very hard to find but not expensive. There are a couple of options however.

For now I have gone the route of using 6AT7 instead of 6AX7 with the 60mu instead of 100 with no detrimental effect or volume change. The initial tube to replace the chinese is a canadian Rogers 6AX7 NOS & was a big improvement, however after putting in a euro NOS 6AT7 the sound has improved again. The main tubes are RCA 832A NOS, not only do they sound great but look really funky too. The other option would be to rewire to suit the 12AX/AT7 types, a simple fix for those handy with a soldering iron.

 

The specs say 32-600 ohms headphones & 1W but do not say what it is @ the different impedences. For now using the low impedence AKG241 headphones. At 12 o'clock position it is plenty loud. Plan to buy some Fostex TR50 ortho's in the near future, as I think this amp has the oomph to do them justice. The AKG241's have never sounded better & have more base & cleaner highs than in previous amps.

For a total of $250 this is an amazing bargain IMO. It does run hot so needs plenty of space, but would not recommend it for desktop/speaker set up due to the heat issues. No safety frame comes with this. A switch at the back allows speaker or headphone use. The manual is one sheet of paper in chinese so your on your own there. I do not know all the appropriate words for describing the sound but sounds great to my ears. Good firm base, rich mids & smooth highs & great detail throughout.

 

From the sales blurb they probably had high impedence phones in mind but list from 32ohms up, so took a chance but so far has worked out great.

 

From the seller (translated):

 

The real price of civilians 6n2 + fu32 fever headphone amplifier

Finished with a floor machine

All hand welded scaffolding

 

6n2 + FU32 Sakunami tube single-ended output 4w +4 w, amp output 1w,

And all of my products, comments, suggestions, criticisms, is my greatest support and encouragement, I have to create the world's most cattle Mic ---- cheap good sound, so that more people enjoy the fun of this part on the ear feel good to hear the sound through, improve quality of life for the ears. Tube amp can not get rid of desire and mysterious, expensive veil.

Pure tube amplification and power amplification CPI-end amp choice! Contrast RP030 million class amp standard (not a tube amp gallstones can compare). First used in particular to promote the headphone output transformer, protecting you against hundreds of thousands of dollars of damage to high-end headphones, the real price close to the people for only 568 yuan a table,

We listen using Sennheiser Sennheiser HD800 flagship dynamic headphones

Optional power supply 110v 220v to 110v please and after explaining our shoot, normal delivery is 220v

 

 

Power cord Signal cable supplied (that is on the computer's power cord) due to safety issues related to the preparation of your own, do not provide the finished machine

Sennheiser HD600 HD650 HD700 HD800 series headphones perfect match

 


Product Features

A push by Beijing 6n2 tubes and Beijing fu32 Class A vacuum tube amplifier circuit in parallel, using the output transformer output

2 core output transformer using Z11 0.35MM 66 * 32 wafers using special processes around the system, power supply using H 14 360

0.5 annealed wafers

3 along the line audio input, perfect headphones protection circuit, output transformer no-load protection

Four former senior designer fever seniors (old driving New) provide a prototype circuit, and then have experienced fever seniors (gall Arts Presbyterian)

Improved circuit, put on a prototype, which took six months of selecting components for adjusting the sound improved, setting production sale, bulk

Production strictly in accordance with the sound when adjusting component assembly

5 goals headphones and listen to the sound description

6 Listen with headphones as: flagship Sennheiser HD800 headphones with the machine and Italy RP030 Professional

Headphone Amplifier contrast audition

7 sound described as: 6n2 + fu32 two headphone amplifiers for a fever, in the audio band with excellent performance, high-quality ear

Player, the overall balance of low and medium frequency, with the CPI tube characteristics, the full sense of low volume and intensity, IF warm alcohol

Thick, high-frequency has special advantages, the entire frequency layer

Times clear, with great accuracy, but did not split at very high frequency sound detail, stretch and bright high-frequency

Be controlled very well! This paragraph sound performance overall service, praised the high cost can be put headphone amp

Generosity

Product Features

Sources may use audio CD player and a computer (PC with a sound card line-out port on the need)

A use of all AC filament lighting, with 102DB headphones listen, hear a little hum noise, feel, and do not

Like the static power

1 uses 6n2 driven fu32 parallel CPI amplifier circuit, power amplifier output 4w +4 w push speakers with impedance requirements

(4 - 8) ohm two-way speaker, sensitivity 90db above 6.5 inch, headphones 32-600 Europe (1w or so)

3 volume potentiometer type used in Japan ALPS 16 potentiometer, ensure clear positioning and left-right balance

4 with accuracy up to 1% metal film resistors and import electrolytic capacitor. Coupling using imported oil capacitors

5 uses 0.8mm brushed stainless steel surface with wooden chassis,

Performance Specifications:

The machine output characteristics, 4 ohm output port directly, 8 ohm output and a headphone jack switch

1, the product full name: 6n2 + fu32 amplifier + amp vacuum tube amplifier with two machine

2, Color: brushed stainless steel surface qualities

3, Weight: 6kg about Taping Dimensions 40 * 35 * 25cm

4, Product Size: Size 32 * 18 * 16cm height with tube

Parameters Table

· Input: one RCA input

· Output: behind the amplifier output impedance of 4 ohms Interface 8 ohms two set of interfaces 4w +4 w

Front 6.35mm standard headphone output hole 32-600 Europe

· Frequency response :26-38KHz ± 2db

Output SNR:> 118dB "A" - wtd

Output total harmonic distortion: <0.008% 10Hz to 20kHz

· Amp maximum output peak: (1w left) (corresponding to the power please correspond headphone impedance calculation)

To provide this special thanks to the local senior prototype circuit fever predecessors (old driving New)

Quality Warranty tube package with two months, the whole year of free maintenance, warranty, all within the freight buyer

...................

 

From another supplier:

 

TUBE amplifier is not like other transistor and digital amplifier.it's 4W*2,but it's support 20-100W speaker,no problem.

about Headphoe 6.35 JACK output:1W,perfact for 32-600ohm hadphone.free give one 6.35 to 3.5 converter,then you can connect it to all headphone

post #2 of 56
I was pondering that amp before I bought my Little Dot, I liked the look of tubes in it. Then I ran across a page with different tubes and the same amp for less than $150 so I took a pass on the Chinese one.

I'll try to find that page again if you want it.

Sent from my HTC Desire HD A9191 using Tapatalk 2
post #3 of 56
Thread Starter 

I think I know the one you mean, but does not have the headphone output, or the funky 40's tubes

 

This one?

 

Processed By eBay with ImageMagick, R1.1.1.M2a

post #4 of 56

i just ordered one of this amp.

also i ordered  some NOS GU23 to replace the  chinese FU32 and a NOS 6N2P-EV to replace the 6N2

Thanks to your info i also ordered one NOS 6AT7.

post #5 of 56
Thread Starter 

Great, let us know what you think of this amp, but give it time to show it's full potential. A minimum of 1 but 2 weeks burn in is better. These larger tubes

definitely take longer to burn in than the miniatures. Enjoy.
 

post #6 of 56
Quote:
Originally Posted by DavidK35 View Post

I think I know the one you mean, but does not have the headphone output, or the funky 40's tubes

 

This one?

 

Processed By eBay with ImageMagick, R1.1.1.M2a

Yeah that was the one, I saw it on the SiliconRay site.

Your right no HP Out, I totally missed that.

 

Those fu32 look just too cool but the RCA's look even better and probably last longer as well.

post #7 of 56
i received the amp today.
bad news, it came with one broken FU32 tube and seller refuse to send me a new tube but they just want to partial refund of $5
DONT BUY FROM 85China.

not good enough.

so i just order a set of GU32

i open it up and one of the big filter capacitor came off the mounting and it was just loose inside.BAD

so i remount it and i made an aluminium clamp to secure it in place so it does not come off in the future.

will post photo later.

can not test it.. will be waiting for the replace ment tube GU32

NOW

a couple of questions

- when im using a headphone, does the amp need to be connected to a pair of speakers while using the headphone? can i use headphone without connecting it to a speakers?
- the switch at the back, what is the position of it when listenning to a headphone and speakers?
- what is the best tube to replace the chinese 6n2?

This the photo of the capacitor after I install an aluminium clamp
DSCN0067.JPG
Edited by jhin - 7/16/13 at 3:31am
post #8 of 56

Any updates on your impressions of this amp?  I have one on the way too.  Plans are to swap the tubes for NOS and put it in a decent looking chassis.

 

Regards

 

Jon'.

post #9 of 56
Thread Starter 

You do not need to connect speakers.

Yes you can use just headphones.

Headphone position is up.

IMO the best replacement is US/Euro NOS. 6AX7 & 6AT7N I have used both & are fine, the 6AT7N is my preferred option & does not really affect the output volume.

 

For pure cosmetics I am going to replace the volume knob, to match other gear.
 

post #10 of 56
Thread Starter 

Just noticed in my original thread starter post, the "other option" to rewire to suit 12AX/AT7 is regarding the 6N2/6AX7 tube not the main tubes.

 

Wiring diagram: http://www.triodeel.com/images/rb6n2pcv.gif

post #11 of 56

Am I right in thinking that the 6AT7N is interchangeable with the 6DT8?

 

Regards

 

Jon'.

post #12 of 56
Quote:
Originally Posted by DavidK35 View Post

You do not need to connect speakers.
Yes you can use just headphones.
Headphone position is up.
IMO the best replacement is US/Euro NOS. 6AX7
thanks for the info

im just waiting for the new tubes
i just made a new side panels for it. the ones the came with it is just to ugly ( pine wood with red stain).


DSCN0071.JPG

DSCN0073.JPG

I know it will not improve the sound quality, buy I just looks better



i will also replace the volume knob. i have a lathe, i might machine an aluminium or wood.
Edited by jhin - 7/20/13 at 3:26am
post #13 of 56
Thread Starter 
Quote:
Originally Posted by Jonnville View Post

Am I right in thinking that the 6AT7N is interchangeable with the 6DT8?

 

Regards

 

Jon'.


Yes that is right, if you do use that tube let me know what you think of it.

post #14 of 56
Thread Starter 
Quote:
Originally Posted by jhin View Post


thanks for the info

im just waiting for the new tubes
i just made a new side panels for it. the ones the came with it is just to ugly ( pine wood with red stain).


DSCN0071.JPG

DSCN0073.JPG

I know it will not improve the sound quality, buy I just looks better



i will also replace the volume knob. i have a lathe, i might machine an aluminium or wood.


Very nice panels, when you have all the mods completed post more pics.

post #15 of 56

Here is the photos of the finish modded Civilian 6n2+fu32 tube headphone amp.

I made a wooden front panel.

I replace the original switch with a rotary switch to match the volume knob.

I also added a green LED on top of the headphone jack ( its not connected yet )

 

The back stay the same.

 

I still dont have the replacement tube..=(

 

 

 

 


Edited by jhin - 7/24/13 at 6:53pm
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