[hifimanrookie]

Ok, many people reading this will probably think that i'm either lying (see attached pic though) or deaf but here goes:

Upon receiving my DV 337 I imagined using it with my HE-500 and especially the Senn HD-800.  I also own a HifiMan HE-6 but never, ever imagined that I'd be able to power it correctly on the 337.  Of course, out of curiosity I did give it a try and almost fell off my chair upon hearing that it actually performs well!  

Setup:  Macbook Pro-- USB to Violectric V800 DAC, output volume at 90%---Atratus RCA interconnects--DV 337 powered by TungSol 5998 and RCA 6504 (metal, red) tubes---Toxic cable--HE-6.

I normally listen to classical at low-normal volume, using my V-200 amp with the HE-6 the volume dials are usually at 9-10 'o clock, with the 337 I'm currently listening to Schubert with the volume dials at 12.  That's plenty loud for me, bass is full (put on an organ concerto to check), the highs are not clipped or distorted, nothing like that, just a clean tube sound and to my ears a good pairing even though the impedance of the 6 is only 50 Ohms.

Frankly, I don't understand how this is possible.  OK, it's a dual mono design but powering one of the most inefficient headphones on the market???  I wonder what the output is, DV are a bit cagey about this but going from what I hear it can't be less than 1 W/channel into 50 Ohms.  The HE-6 documentation specifies a minimum requirement of 2W for an amp and my comparison point (the V200) delivers 2.75W.

If anyone has some sort of explanation for this then by all means, share.  

I BELIEVE U! As that amp looks similiar to me.. and its funny u sound so surprised..just like i was when i heard him before i bought it on the spot
I told u when i sold it to u..this particular 337 is modified by the first owner...thats why he is probably so good... No one believed me that this 337(nick name 'the evil one') would be this good as ur also expressing now..i knew this already..am glad u experience it also now urself..u dont need to excuse urself for that..i know myself almost no one believed me when i said ur amp is something special..but i have to be honest..never thoight it would be able to drive the he6... Damn..why did i sell my 337..

Am glad its exceeds all ur expectations...and i hope others will see that the 337 can be something special...did u try other pairs of tubes? I can promise u that if u find the tungsol sj7gt mesh plates (drivers) in combo with the tung sols 5998 or bendix 6080 WB with slotted graphite plates u will be in for a big surprise!

Enjoy ur amp my friend..am glad u like it just s much as i did...

tip..dont mention it on other threads as somehow no one will believe u as its not shiit or emotiva branded..
As i said this amp react well on powercables..did u find a set already through ur friend at sennheiser?

Ps..i am guessing u mean RCA 5693 red hots instead of rca 6504? Or is this a model i didnt know about..did u compare it to the red hots if they are different?
And good choice choosing a toxic cable

Ps..if all goes well there will be a benelux headfi meeting this year..would love to see u there, shake ur hand and try ur he6 on my new amp (will be delivered in febr) and would love to see 'the evil one' again

 

[kramer5150]

Just throwing this out there... there are at least 2-3 different versions of DV337, with MANY internal design changes over the years.  Its been a rolling design change since its intro, with changes made to power supply resistors, capacitors, output coupling caps... and I think theres been a rectifier change as well (but don't quote me on that last one).
 
The biggest change has been an overall increase in output coupling capacitance.  The earlier models had ~50uf-400V caps, which was not nearly high enough for impedance loads in the low 40-Ohms.
 
So depending on which version you get... it could be a night and day difference in terms of low-Z synnergy.  I *think* you are one of the few who use the 337 with low sensitivity, planar magnetic cans. (Others please correct me if this is not the case).  They are spec'd at 38 ohms, but I'd be surprised if their impedance curve and overall Z-characteristics are the same as a traditional ~35 ohm voice-coil driver.... for which many OTL amps get a low grade.
 
Anyhow... thanks for the feedback.  Ive been wanting to try mine with the HE-400.

 

[hifimanrookie]

Just throwing this out there... there are at least 2-3 different versions of DV337, with MANY internal design changes over the years.  Its been a rolling design change since its intro, with changes made to power supply resistors, capacitors, output coupling caps... and I think theres been a rectifier change as well (but don't quote me on that last one).

The biggest change has been an overall increase in output coupling capacitance.  The earlier models had ~50uf-400V caps, which was not nearly high enough for impedance loads in the low 40-Ohms.

So depending on which version you get... it could be a night and day difference in terms of low-Z synnergy.  I think you are one of the few who use the 337 with low sensitivity, planar magnetic cans.  They are spec'd at 38 ohms, but I'd be surprised if their impedance curve and overall Z-characteristics are the same as a traditional ~35 ohm voice-coil driver.... for which many OTL amps get a low grade.

Anyhow... thanks for the feedback.  Ive been wanting to try mine with the HE-400.

I dont know to who ur replying with this post..but i do know there had been lots of internal changes on the 337... But i have to correct u on something...the newer versions are perfect to drive a he500... And many do that..so i dont know where u get ur info from that its rare that 337 owners dont use it to drive a planar... The he500 and the hd650 are the best pairing with the 337 i came across! So the he400 would probably be driven well also.
And dont forget..his 337(it was mine by the way!) is heavily modified... I had my 337 driving the he500 on 22:00o'clock volume... And i had 3/4 of the volume reserve (goes to 18:00 max) to spare...

If u never experienced a 337 in person u cant honestly say it cant drive a planar magnetic.. Just try one with ur he400.. Ican already tell ya now u will be very surprised how a otl amp for gods sake can drive a hard to drive planar at low ohm...

It always surpiprises me people saying that its hard to believe that a 337 can drive a (in my case) a he500 perfectly and sou ding wonderfull with it.....

I just wanna ask u..Before u say that..TRY ONE.. U will eat ur words i can promise u that...

But i have to be honest..hearing that my ex-337 capable to drive a he6 surpised me also..but i totally believe it..as i know how good it drove my he300/400 and until recently my he500!

Just try one..or a 339 ofcourse..its sibling.

PS!!! I agree totally with u that most affordable OTLbased tube amps are Rubbish with low ohm phones..but somehow the 337/339 is a exception..i know that by own experience having owned one for 2 years and using it at least 3-4 hours a day without any faults or hickups! That last thing is to prove that people saying a 337/339 isunreliable is a total fairytale..it not more faulty then a bottlehead or wooaudio..its just how u use it..

 

[Ultrainferno]

337/339 drive HE500 very well. The HE400 can be driven by anything though, it just needs to be plugged in

 

[kramer5150]

It was just a general comment.
I have updated my statement above though to more correctly reflect my line of thinking.
 
I think the important factor readers need to keep in mind though is that not all 337 designs are the same, and there are major differences between the various renditions.
 
Heres mine, an early example, with 50uf coupling caps and big green ceramic power resistors.

 
Heres the version that had a couple www reports of power resistor overheating.  Note the resistors with gold anodize thats baked/scorched off from the heat.  I think these reports are where the 337 reliability questions come from.  AFIAK this is the ONLY circuit layout that has reliability complaints.  My older layout shown above has been very reliable, minus a blown fuse once.  Note you can also see the additional Vishay capacitor they added to the output stage, the bright green one.
 
See rockgrotto forum thread here

 
Smoked resistor close-up.

 
Yet another rendition... but with additional Vishay caps.  Power supply caps look different too.  Notice also this one has gold anodize resistors that are fading from heat.

 
I think this is the current model... even more caps, and additional resistors to better handle heat.  Note this version might also have different value resistors.

 
Notice also some versions have RCA preamp outputs too.  I think the key point is that not all 337 amps are the same, the only way to really know which one you have is to take the cover off and look at the component layout inside.

 

[hifimanrookie]

It was just a general comment.
I have updated my statement above though to more correctly reflect my line of thinking.

I saw that..but ur way of thinking is a general one of which i dont know where that comes from...I AM NOT ONE OF THE FEW USING a 337 to drive a planar..i was at a meeting and ALL people there liked how it sounded through my he500.. And most said that if they had the budget they would buy that pair...
Only one had its doubts about the way it wasnt sounding like a tube amp..i think it was u ultrainferno my friend..u were there with ur wooaudio amp if i am not mistaken..

But somehow there is a general thought that a 337/339 cant drive a planar well...and funny is that EVERYONE saying that..NEVER EVER heard a 337/339 or even saw one for real... They say it just because its a otl based amp..

its like we all said that a diesel powered car cant ever compete with a car running on petrol.. And we all know what happened on the 24hr lemans being won by diesel powered audi's the last few years... I always say: try one... Or else go back to ur emotiva or shiit stuff.

 

[Ultrainferno]

Only one had its doubts about the way it wasnt sounding like a tube amp..i think it was u ultrainferno my friend..u were there with ur wooaudio amp if i am not mistaken..

 

 
I brought a couple of amps but no WOO. I didn't say I didn't like it, I said the 339 sounded more tube-ish than your 337 which sounded faster like a solid state. I preferred the tube sound but your amp powered it more than sufficiently

 

[hifimanrookie]

I brought a couple of amps but no WOO. I didn't say I didn't like it, I said the 339 sounded more tube-ish than your 337 which sounded faster like a solid state. I preferred the tube sound but your amp powered it more than sufficiently

Oopsie My apologies for saying u had a woo with u
But i can remember u saying that my amp was to much solid state sounding for ur liking, never forgot that for some weird reason

Am glad my baby found a new owner who appreciates it just as much as i did..that was very important for me..as i care a lot about my stuff..just like i did with my modded mstage i once had and which i sold on that particular meeting to a couple owning some grados 325

 

[kramer5150]

Aah ok then... Let it be noted that my speculation above has been corrected.   There are more members than I had originally thought using planars with the 337... with excellent results.
 
Either way, it is a great amp and I enjoy mine a lot.

 

[hifimanrookie]

Aah ok then... Let it be noted that my speculation above has been corrected.   There are more members than I had originally thought using planars with the 337... with excellent results.

Either way, it is a great amp and I enjoy mine a lot.

I saw that now..nice pics by the way..
Maybe u can try a newer model? Or try the amp ultrainferno uses..the more modern 339.
I had the model with the horizontal row of caps..thats last pic. But as far i can remember the caps were of different color..

 

[Ultrainferno]

I saw that now..nice pics by the way..

Maybe u can try a newer model? Or try the amp ultrainferno uses..the more modern 339.
I had the model with the horizontal row of caps..thats last pic. But as far i can remember the caps were of different color..

 
Used. I have a custom made 300B amp for my orthos now. The 339 gathers dust like the best

 

[hifimanrookie]

Used. I have a custom made 300B amp for my orthos now. The 339 gathers dust like the best

Cool!

So ur going to sell urs soon? Just like i did?

 

[Ultrainferno]

no I'm a bit of a collector

 

[Xenophon]

Already relieved that you guys don't think I'm delusional.  HifManRookie:  purchasing your 337 was value wise amongst the best deals I've done in HiFiland last year. Closely followed by a pair of Tung-Sol 5998 for 55 EUR which I scored NOS from a guy who mentioned in capitals on his page that he had purchased a huge lot of tubes and was selling them on but knew nothing about them, couldn't test them, offered no warranty whatsoever and sold=sold.  I took the gamble and lo and behold, they arrived pristine, in their original box.  Turned out he had purchased the stock of some French army depot that was being cleared and all those tubes had just been sitting there, untouched, for decades.  If I had known I'd have purchased 10 pair, they're all gone now.  Anyway, glorious sound together with the RCA's.  Am keeping my eyes open for a pair of GEC curved brown base 6AS7 but those I've seen so far are hideously expensive and I'm not sure if they're worth the premium.
 
Frankly I don't understand how these DV/La Figaro tube amps are not more popular.  I was already impressed the first time I saw a pic of one that was open when I noticed the neatness of the wiring.  Call me stupid but neat wiring indicates an attention to detail that usually goes together with a good product.  If you compare that to some of the competitors.... (Stereophile of last month showed a pic of a Sophia Electric selling for >2000 USD with wiring that looked like hell, bad soldering, components bent (!) so they'd fit the chassis.  Typically, although they remarked on that and despite measurements being out of whack, it got a glowing review...).  
 
My only regret is that I'm flying back to my base in India wednesday and will have to leave the amp behind in Europe until my next visit.

 

[kramer5150]

  Already relieved that you guys don't think I'm delusional.  HifManRookie:  purchasing your 337 was value wise amongst the best deals I've done in HiFiland last year. Closely followed by a pair of Tung-Sol 5998 for 55 EUR which I scored NOS from a guy who mentioned in capitals on his page that he had purchased a huge lot of tubes and was selling them on but knew nothing about them, couldn't test them, offered no warranty whatsoever and sold=sold.  I took the gamble and lo and behold, they arrived pristine, in their original box.  Turned out he had purchased the stock of some French army depot that was being cleared and all those tubes had just been sitting there, untouched, for decades.  If I had known I'd have purchased 10 pair, they're all gone now.  Anyway, glorious sound together with the RCA's.  Am keeping my eyes open for a pair of GEC curved brown base 6AS7 but those I've seen so far are hideously expensive and I'm not sure if they're worth the premium.
 
Frankly I don't understand how these DV/La Figaro tube amps are not more popular.  I was already impressed the first time I saw a pic of one that was open when I noticed the neatness of the wiring.  Call me stupid but neat wiring indicates an attention to detail that usually goes together with a good product.  If you compare that to some of the competitors.... (Stereophile of last month showed a pic of a Sophia Electric selling for >2000 USD with wiring that looked like hell, bad soldering, components bent (!) so they'd fit the chassis.  Typically, although they remarked on that and despite measurements being out of whack, it got a glowing review...).  
 
My only regret is that I'm flying back to my base in India wednesday and will have to leave the amp behind in Europe until my next visit.

I really want to get an HE-400 to try out with mine, now that they're on sale for $299..!!!
 
I think its the availability that scares people off on the DV/LF amps.   The companies just don't have a www presence here on HF, and you're forced to buy them from foreign (depending on where you are located) retailers.  Beneath all cosmetic beauty, the internal wiring, component and trace layout on these amps is unmatched for the $$$.  Theres just something I find appealing about an old-school, point-to-point component layout, where you can really see what everything is doing in the signal chain.
 
My amp was totally TRASHED by US customs who did a HORRENDOUS job re-packing the amp as it passed through US borders.  I don't have pictures, so you'll have to just trust me on this.  They just threw the amp back into the box without securing it in the foam shock packaging.  A corner of the amp chassis had punctured the corrugated outer box, the tube cage banana-plug pins had been sheared off and were lose rattling around inside the chassis, the tube cage was crushed into a trapezoid, and the large toggle on/off switches were busted off.  Luckily the TS 5998 and mesh-plate drivers had managed to stay in their individual cartons... which were also loosely bouncing around inside the box with the amp!!  Its a HEAVY amp, and if you can imagine the amount of impact-force needed to do this kind of damage.
 
I was able to replace the switches, re-paint the tube cage and touch up the chassis with DuPont / Sherwin Williams metallic gray automotive paint (fortunately DV used one of the standard colors!!).  I think it says something about the physical robustness of the circuit, components selected and the structural design of the chassis.  I don't think too many amps this big/heavy would survive what mine has gone through.  Anyhow... here's a pic.  After all I have been through with this amp, its not going anywhere... with the TS tubes it sounds great coupled with output transformers powering any of my low impedance cans.