[Acapella11]

Agree with Audiofanboy, I would not get the upgrade tubes from LD.
 
Respective the choice of upgrade tubes, it all depends on the brightness of your headphone. If it is as relaxed as the HD650, the 6H30P or 6H30P-EV  power tubes + CV4015 could be just what you want. I am not sure - but I think I've read the Beyerdynamic DT1350 is not exactly that relaxed. If this is the case you may want to consider a pair that fits better otherwise the sound might get too bright. For example 6H30P (-EV) with Mullard M8100 or Tung Sol 6AJ5. Another pair would be based on the CV 4015s, then paired with with 6N6P-IR (my favourite) or nice 6N6P. What I would not suggest to do is just to fit the driver tube to the power tube, but rather the other way round. The 6H30P tubes sound great, are regarded high and they are expensive. So you kind of want to keep them. But, I personally think the CV4015 is the upgrade to do and then I would fit the power tube to it. If you first get the CV4015 only, you can find out whether you like the sound. I would take it from there.
 

 

[hallom]

Hai Tuberollers!
 
I got a pair of CV4015 from julienbell92, thanks for him this way too, he still has some, if you are thinking about them night and day like I did lol. They are Philips made, one is in '72 the other who knows, but the paper box was similarly yellowed
 
So, upon first listening: indeed they are neutral and have the emphasis on the mids, just as much as I miss the punchy subterranean bass from the 6J1P-EV gold platinum grid's. Not that they lack of bass but its just not that authoritative and present compared to the latter, however they have more space in them which is a good thing. And funnily they sound better, particularly bass-wise with the Sovtek 6H30-EV's, whereas the 6J1P-EV's are better with 6N6P gold grid's. But unfortunately I don't like how the 6J1P-EV's bass loosened up with time - still punchy but less precise, - they became a bit too tubey for me, but not overly disturbing, I might give them an other chance after having some time with the CV4015's.
 
So Acapella11, do you say 6N6P-IR further improves the CV4015? I would go with the DR supertube, but costs too much for me now to justify it.
 
Only if I could combine the precise and punchy bass the 6J1P-EV had in the beginning (I thought yes! I have found the one tube rules all) and the neutrality and soundstage of the CV4015. But I start to realise the law of compromise is in effect here too.
BTW according to your experience how does the sound of the CV4015 change when burned in? Do they also loosen up like 6J1P-EV?

 

[Audiofanboy]

My experience with burn-in on the CV4015 was that the bass got noticeably tighter after a couple dozen hours, a bit more clarity, and the treble got ever-so-slightly less sibilant (it wasn't actually sibilant, but a bit spiky, still is on some songs now). But they sounded balanced, wide and airy even new.
 
Looking forward to your impressions after burn in of those '72 tubes!
 
I just won an auction for 28 EF91/CV138/CV4014 tubes, so expect a new EF91 shootout in about a week.

 

[Audiofanboy]

Reading over the last post again, I do remember the same odd "loosening up" on both kinds of 6J1P-EV i tried.
 
First pair "6sh1p-ev" '71, rocket, CCCP, no grooves, sold as '75s from some dude in Budapest were absolutely awesome out of the box. Balanced and detailed, bone dry bass (like the CV4015 actually) and great treble that made my ears bleed, but great yet painful. 95 hours later they had transformed into balanced dull tubes with tight-ish bass and rolled off mids and treble. Never liked them again...
 
On my 6j1p-ev gold grids, grooves, rocket, from '86, I found the sound punchy and very V-shaped out of the box, detailed but no really airy. Didn't like them as much as my other pair because they were less balanced and the bass seemed kind of garish or not-true-to-life. 105-110 hours later they had become a perfectly enjoyable v-shaped (not V anymore) clone of the M8100/CV4010, a bit less warm and with more authoritative bass. Last I listened to them paired with the 6n30p-dr, they were probably my 2nd or 3rd favorite 6ak5/ef95 tube. I could live with these as drivers if I needed to.
 
The CV4015 did the exact opposite after burn-in. Started looser and became tighter; very tight in fact. Hope that helps compare the burn-in experience with the 6j1p-ev a bit.
 

 

[hallom]

Thanks man, I'm getting more and more curious

 

[Audiofanboy]

Btw, anyone else using an MKIII or IV with Hifiman HE-400 or 500?
 
I just got a pair of HE-400, and I'm wondering with gain setting might work the best to drive these. So far, gain 10 seems catastrophic (no bass, bleeding highs) and 3 seems to lack definition (tons of bass though); I'll try 4 and 5 tonight and see... Kind of looking for a gain setting I can use with both the HD650 (x10 up to now) and HE-400.

 

[mab1376]

Quote:

Btw, anyone else using an MKIII or IV with Hifiman HE-400 or 500?
 
I just got a pair of HE-400, and I'm wondering with gain setting might work the best to drive these. So far, gain 10 seems catastrophic (no bass, bleeding highs) and 3 seems to lack definition (tons of bass though); I'll try 4 and 5 tonight and see... Kind of looking for a gain setting I can use with both the HD650 (x10 up to now) and HE-400.

 
 
I don't think OTL amps are really designed for low impedance/high demand ortho headphones.
 
Yeah you'll get some sound, but I'm sure it'll be far from optimal as you've already found.
 
Personally I have the HE-500 in my sights and I plan on either using a good solid state amp, or saving for a Woo WA22 since it is transformer output and has much more output power.

 

[Acapella11]

Hallom, to be honest, I don't remember the exact changes over the burn in period, but I remember that I first wasn't enormously convinced by the bass, however anything else =). What I can say now is that they feel punchy, the quality is very good and quantity is totally fine for me. The 6N6P-IR add some deep bass, which I very much like. They are also V- or rather even U-shaped for that matter.
 
Just wait until your burn is complete and see how the bass is then. Personally, I would find it more interesting to try the 6N6P-IR than getting another pair of 6H30P tubes (-DR in this case). Although, to be fair you will probably buy the best of those. But, be not worried that 6H30P > 6N6P, generally speaking, but 6N6P-IR starts with 6N6P... They produce quality sound and you wouldn't spend as much money. Of course I cannot give any guarantees . Pairs of tubes sound differently too and tastes vary.
 
As Audiofanboy described, I also noticed differences between 6J1P-EV tube pairs and the burn in was similar for me. My favourites were from 1975 because of a stronger bass. To be fair, I liked the 6J1P-EV tubes more in the beginning with a sparkly treble, they sounded more exciting.
 
Audiofanboy, I have HE-500 headphones and run them on the LD MKIII, which is generally considered a no go (and I actually like it with the tubes I have ). I am going to upgrade sometime soon tho. HE-500 and HE-400 are quite different in terms of demands on the amp. HE-400s are definitely easier to drive and hence a logical option for the LD MKIII or IV. In fact they might be superior for some people to the HD650 because they are supposed to sound really good even without highend amps while the HD650 rather require highend amps to really shine . Also if you like a faster and opener sound signature, you may prefer the HE-400s. Because the HE-500 is more difficult drive, I assume, I am using a gain of 10 at the moment. I do lose some dynamics when going down to 5. On 10, however, the volume knob is only turned to 12 o'clock max while I am listening. Formerly, I always used 5 (AKG Q701) and I thought it was the best setting in terms of dynamics and focus. But the differences were not huge between the settings.
 
Let us know which gain settings you found most useful, as I think the HE-400 may become more of a topic here with it's increasing popularity and if it sounds good with the LD MKIII / IV. After you tried all the gain settings, how do you like the sound?

 

[Acapella11]

mab1376, +1 on the HE-500

. I do not want seed the the wrong equipment discussion in this thread, so I am keeping it short and won't answer further questions . HE-500 and OTL amp can fit nicely. Give this a read: http://www.headfonia.com/lafigaro-339-my-fav-otl-amp/

 

[hallom]

What I can say, the bass has greatly improved even after a few hours, just as Audiofanboy said. It's getting more and more interesting, I'll update you once they are burned in more.
In the meantime, do you have a tip where to find cheap 6N6P-IR tubes? Because the ones on ebay don't seem to be matched pairs.

 

[Acapella11]

OK, let's keep the posts rolling
 
Hallom, I got my 6N6P-IR from this site: http://tubes-store.com/product_info.php?cPath=30_78&products_id=519
 
They are $ 13 / pc + $ 8 shipping from Russia. I actually didn't worry about matching but you can contact them before the purchase in this respect. If I remember correctly, the packaging was done very well and it was delivered within one and a half weeks (UK) although it said 12 days on the homepage. Quite liked the service.

 

[Audiofanboy]

Yeah, I know than OTL amps are by definition not well suited for driving orthos, but I can't exactly justify buying yet another headphone amplifier... And I do like the tube sound coming out of my maxed out IV SE. From what I'd read, the HE-400, and by extension the 500, should be about the only orthos "driveable" by OTL tube amps such as the MK III/IV (and I've seen more than a few people with that setup around here). If it can be driven by an iphone (even poorly), the 100mW of the MK IV SE should at least get it moving correctly at reasonable levels?
 
Anyway, after an evening of testing the HE-400 on the IV SE (reviewed with the CV4015, so we're still on topic here, somewhat) and playing with the gain switches, here's what I heard. x3 gain is ugly. Not unpleasant but bloated and lacking in resolution. For a while last night, x4 gain seemed to be the best compromise, so did x5, with some bass and pretty good separation and decent soundstage. But, putting the amp back on x10 gain as Acapella had suggested definitely shows better resolution and instrument separation (which is why I had the amp in that position with the HD650 in the first place, plus it seemed reasonable to max out the gain with a hard to drive ortho).
 
There is still some getting used to with the HE-400, but x10 gain might be indeed be the best setting, all things considered. It seemed catastrophic yesterday probably because the HE-400 felt tonally out of whack compared to the HD650. Still, on gain x10 or even 4 and 5, I do find that the bass (like below 80-100Hz) is somewhat lacking. It's there but just not as much as I read it is supposed to. This might not seem abnormal if you come from the K701/702 but coming from a well amped HD650 in an optimized setup, I was used to hearing more bass (not sub-bass, which the 650 kind of rolls-off).
 
Btw, I'm having some treble wrapping my head around the whole output impedance, load impedance, damping factor thing between different types of headphones and amps, but correct me if I'm wrong. On an OTL tube amp with very high output impedance paired with an low impedance ortho, the damping factor is really low. The higher the gain on the amp, the more voltage I'll output which should be able to make the headphone louder, but might not give them more current and might not drive them better. If I lower the gain on the amp, more negative feedback should be going on, which improves the damping factor, which might help driving the headphone...? Or am I just confused? Just trying to make sense of what I hear...
 
About the HE-400 and CV4015, after a few hours I am hearing some glorious sound though. Outrageous airy detailed flying treble, gorgeous and fleshy clear upper mids and mids, and a solid mid-bass kick that is making me rediscover rock music after a falling out for a few years. Just the bass is troubling me. Maybe it is the CV4015 that isn't giving me enough bass and sub-bass in this setup, or maybe the IV SE really isn't optimal to drive the HE-400 (even though I really am starting to like what I'm hearing).
 
In terms of volume, on x10 gain, I don't usually go over 9 o'clock for music and 10 or 10:30 for videos (sound in videos). Acapella, what do you think of the 6AJ5 paired with the HE-500 btw?

 

[mab1376]

I just ordered some 6N6P-IR tubes to try with my 6AJ5 tubes.
 
Had no real reason other than curiosity of the sound signature.
 
I'll post some impressions once i get them burned in.

 

[Acapella11]

Audiofanboy, you have been deeper into this topic than me but what I read was that in an ideal case scenario the output impedance of the amp should be 1/8 of of the impedance of the headphone, that is to allow a linear frequency reproduction. This is a good guide line but there surely is a tolerance. Only if you move too far away from the ideal, the mids will be bumped relative to over frequencies, if I remember correctly. Then, the 6H30P tubes are really good with mid bass but not as good with with deep bass, I thought. Maybe this was less noticeable with the HD650 but now becomes more obvious with the HE-400 (deep bass? try some 6N6P-IR ). Deleted entry - just flew over your text first time .
 
6AJ5 are great sounding tubes but because the HE-500 converts all the power it can get from the LD into dynamics, the 6AJ5 sound a bit too anemic, whatever power tube you take. You really can get addicted to the mids, which are already great with the HE-500 but it just isn't lively enough for me.
 
mab1376, cool. What are your current power tubes? Please keep us posted.
 

 

[mojorisin35]

Ordered my mkiii....the wait.... I have some 6n6p gold grid on the way. These ones
http://www.ebay.ca/itm/350688546177?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649#ht_5446wt_1150
And I am looking for sylvania gb5654 gold grids are these similar at all?
http://www.ebay.ca/itm/120742819812?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649#ht_500wt_689
I would also like to find some Hytron 6AK5WB to try

And it begins....
Gary