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Hifiman EF-5 headphone amplifier mods and rolls - Page 5

post #61 of 111
Quote:
Originally Posted by inter voice View Post
 

12AV7 Sylvania?

 

Should it be 12AU7 instead.  I have tried Sylvania 12AU7 and it is very good indeed.  However I am now using RCA clear top 12AU7 which is very similar to Sylvania.

Yup, 12AV7. Works fine. No distortion. Others tubes i have or tried are:

 

Stock Full Music

Mullard CV4003

Tung-Sol 12AU7 (Reissue)

Electro-Harmonix 12AU7 (Reissue)

Pope ECC82

RCA Clear Top 12AU7

Valvo/Miniwatt 12AU7

Philips Miniwatt Holland 12AU7

Philips Miniwatt Special Quality 12AU7

Telefunken 12AT7 (no good, distortion can be heard)

GE 12AY7 (no good, distortion can be heard)

 

My favorites so far are the clear top, miniwatt holland and the sylvania 12AV7.

 

EDIT:

 

 

 


Edited by jaxz - 9/7/14 at 11:33am
post #62 of 111
Thread Starter 

Nice shots :wink:

post #63 of 111
Quote:
Originally Posted by inter voice View Post
 

Nice shots :wink:

Thank You!

post #64 of 111
Ok. I just order AD797BR and LME49990, both dual modules with an adapter. Hopefully I will get those in a couple of weeks so I can post some impressions.
post #65 of 111

i have decided to sell my EF-5 amp and will post it in the ForSale forum in the next few days. It is a great amp but I simply have too many amps. I just replaced the filter caps with Panasonics, replaced the diodes with high speed ones, replaced the RCA's with gold ones, replaced the volume control with a carbon Noble. Tubes will include a Full Music and a Raytheon black plate 12AU7 with very few hours.. Asking $275 including shipping and PayPal fee. I thought I would mention it here first in case anyone is interested before I post it. PM me if interested.

post #66 of 111
Quote:
Originally Posted by dpump View Post

i have decided to sell my EF-5 amp and will post it in the ForSale forum in the next few days. It is a great amp but I simply have too many amps. I just replaced the filter caps with Panasonics, replaced the diodes with high speed ones, replaced the RCA's with gold ones, replaced the volume control with a carbon Noble. Tubes will include a Full Music and a Raytheon black plate 12AU7 with very few hours.. Asking $275 including shipping and PayPal fee. I thought I would mention it here first in case anyone is interested before I post it. PM me if interested.

That's an extremely good deal, and I would be interested if I were not considering selling mine as well. I want to buy the Oppo HA-1 as my end game.
post #67 of 111

I tried all my tubes again with the OPA627. My favorite is the Philips/Valvo 12AU7, while Pope ECC82 (Philips Holland) come in close second place.

post #68 of 111
Quote:
Originally Posted by jaxz View Post
 

My favorites so far are the clear top, miniwatt holland and the sylvania 12AV7.

 

 

Ahh the good ole Clear Tops, I had an NOS RCA Clear Top 12UA7 in my dinky little Indeed G3, back in the day. An truth be told I loved it with my DT 990, nice to see it's still a home in nicer amps these day :3 and why Jazx ur listening to it with cans that I've owned or currently own and love! The HE 4 and DT 990 :D go figure 

post #69 of 111
Yup. Clear top it's a very nice tube, and so many others, but for the HE-4 i prefer tubes with much more midrange, like the Philips/Valvo/Mullard.
Cheers!
Edited by jaxz - 9/21/14 at 9:07am
post #70 of 111

which one of these 12au7 would you recommend and why ?

 

http://sklep.lampyelektronowe.pl/?wyniki-wyszukiwania,19&sPhrase=12au7&iProducer=&sPriceFrom=&sPriceTo=

 

I would go blindly to check out tung sol, philips and shuguang

 

thanks a lot

post #71 of 111
Thread Starter 
Quote:
Originally Posted by magicman View Post
 

which one of these 12au7 would you recommend and why ?

 

http://sklep.lampyelektronowe.pl/?wyniki-wyszukiwania,19&sPhrase=12au7&iProducer=&sPriceFrom=&sPriceTo=

 

I would go blindly to check out tung sol, philips and shuguang

 

thanks a lot

I found SYLVANIA 6189W and RCA Clear Top 12AU7 suit my taste best. Both are very clear and with excellent mid range.

post #72 of 111

just wanted you to know that these new tubes are worth nothing

 

seriously, total crap comparing to something from 50' or 60'

 

you'd better go find some old ones on ebay than buy brand new stuff, just total waste of money

post #73 of 111
Quote:
Originally Posted by magicman View Post

just wanted you to know that these new tubes are worth nothing

seriously, total crap comparing to something from 50' or 60'

you'd better go find some old ones on ebay than buy brand new stuff, just total waste of money

So true, just got a swinging deal on a 1950s Raytheon tube, and I can acutally listen to my HD800 now! Magical
post #74 of 111
Quote:
Originally Posted by inter voice View Post
 

You are right that the QC of Hifiman needs improvements.

 

As to the tube being used, I have tried a number of vintage tubes and eventually I settled down with RCA clear top 12AU7.  To my ears it is the best tube to be used in EF-5 and suits my taste most.

 

I have also tried getting hold of the circuit diagram of EF-5 but so far I cannot find anything on it :(. 

Dittos to the OP and others who've noted the low QC of HiFiMan EF5 amps.  I wonder if its unique to the EF5 or a problem across their product line?  I bought mine in February '14 and currently I'm on my third unit (the original and now two replacements).  Their customer service was fine, so I can't complain about that.  Do know that the replacement amps were refurbished units and not new units, and that the replacement units do not come with a new warranty (i.e., your warranty is for one year from time of original purchase even if you have to replace the amp due to QC issues).

 

I love the EF5's sound but the next time it breaks down I'm going to toss it and replace it with something else, maybe a Woo tube unit.

 

Also, the RCA clear top 12AU7 is by far my favorite tube for this amp.  Very nice, balanced, sound.

post #75 of 111

I have been trying many old tubes recently

 

I have found some amazing ones

 

Need to agree rca clear top is superb tube - I guess there was a reason to use it as stock tube in previous ef-5 revisions (and hifiman tried many of nice old tubes when tuning first ef-5)

 

after some burn in of radiotechnique 12au7 (green silkscreens, 60s) find it amazing one, great universal tube for any genre, amazing piano & cello upper harmonics and texturing capabilities, details, depth and low end - this is something you can look forever buying new tubes - new tubes are just completely lifeless, out of emotion and that amazing sparkle, I guess it's all because of ecology now, forbidden materials etc

 

in the 50s or 60s there were not so many restrictions I guess and it affected the sound directly

 

In the past I was in possession of first revision of ef-5 with full music 12au7 gold pin with gold silkscreens - that was really out of this world tube but I did some research why new one that has been added to the newest revision of ef-5 sounds so bad (total crap) - this is budget version with no gold pin

 

there was 1st version of this tube which was the best with gold pins and gold silkscreens then there was gold pins version with red silkscreens (so so tube) and the crappy one now with no gold pins - so beware of many versions of this tube

 

I still need to check out GE 12au7 from 60s

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