Sennheiser HD650

If you liked the WA3, you'd love the WA2. Tube rectification with more channel segregation.

I have and use 3 sets of headphone; but the WA2/HD650 combination hasn't gone away. It's what I prefer for some of the crappy old recordings that I grew up with.

 

You're right--I would love the WA2. I read so much about that, also the LaFigaro 339 & several others. What stopped me, I'm sorry to say, are size & weight: the WA3 was just about the largest/heaviest tube amp I could accomodate in my jam-packed desktop system.

Yet of course I remain curious about how these better OTL designs would sound. I now have 3 headphones that can benefit from an OTL: a heavily modded HD650 ("JAR650"); a ZMF Eikon/300 ohm; and a "unicorn" pre-fazor LCD-2.1/believe they're 70 ohms (just enough to be improved by a high impedance source). Your post reminds me how tempted I am by the WA2 and others.

BTW, I met Jack Woo at CanJam NYC earlier this year and was impressed by the time he spent discussing the WA3 with me. His company has a very solid, friendly vibe--that really was what pushed me over the edge into getting one.

 

Any diehard HD650/600 fans care to describe the difference between these two just on mid range?

 

Consider this a partial response, at best: I am very familiar with the HD650 (both stock & heavily modded), but only heard the HD600 once, briefly. I really didn't care for it, felt no urge to borrow it to listen at greater length. But found out later that it had been modified to some extent by the original owner (unbeknownst to my friend, who purchased them used).

Anyway, the big difference I heard was in the midrange: the HD600 was "shouty," sounding either elevated in midrange levels; or somehow hyping note transients; maybe both. Neither HD650 (stock or modded) sounded like this. Indeed, I love the midrange of the HD650. It manages to be rich in detail, yet not be bright or wearing in the least. The HD650 is all about the midrange. I've heard other headphones that better it in various ways, but that midrange is quite a feat for such an inexpensive, modestly scaled HP design IMO.

 

I have the 580 right here and its the same thing as the 600. Smaller soundstage and more neutral due to the 650s darker nature. Been talked about to death on Head-fi to the point that they have an emote for it. lol.

 

I'm no good expert in trying to convey this stuff in words. I feel the 600 is more forward in upper mids and "seems" to fetch more detail in certain recordings. At first I found this really euphoric. The 6xx is more refined everywhere, has better lower mids and is generally better for different types of recordings. I find the 6xx upper mids less forward and more correct through all frequency plus more lower mid definition. At first I didn't like the 6xx as much but then I realized it's better overall on what I listen to. Now 600 is hard to go back to unless I cherry pick the music for it.

 

Retried the foam with the coin holes in them and I really like it now. I think I just needed to spend a little more quality time with it in this form.

I've actually been neglecting them lately and using my 800 alot, but tonight I'm in a 650 mood. Gungnir Multibit should be incoming in the next week or so... curious to see how much they scale again with a better source since I know Gungnir Multibit is a huge step up from Modi Multibit (having owned both).

Super duper tempted to try spider cage removal. We'll see how long I can hold out, but I feel like it's inevitable.

 

So this is.... surprising.

Bit the bullet and removed the spider cage and completed the KISS mod, even going so far as to follow Marv's exact damping placement (just using the green pieces ... I originally had more pieces applied)



And this headphone completely transformed into a different beast entirely. Just perfect tonal balance and frequency response (even more than I thought possible), alot more micro detail and resolution.

I think I might like it more than my 800 now, which isn't something I ever thought I'd say. 800 still has better imaging, but the KISS 650 just nails everything else.

2019 truly starts with a bang.

 

I just modded my HD650 to HD650M (nickel mod, spider cage removal, and dynamat) and I'm torn as to whether I like it better modded vs stock. The improved resolve, tighter bass (albeit with midbass bloom), and bigger soundstage are definite improvements. The issue is they seem to be a bit edgy now and cause fatigue. Best way to describe it would be having to keep the volume lower to not feel like my ears are throbbing when I take them off. I also feel like there is a slight channel imbalance, but only on mid bass. Its gives the feeling of more weight on one side. I'm thinking about removing the nickel mod and using new inner foams. Amp is a Taurus Mk2 and source is VPI Classic with benz cart and Lehmann Decade phono stage. Any thoughts?

Edit: I should add that I did not have any issues with fatigue or channel balance before modding. So that should rule out the obvious questioning of my turntable setup.

 

They definitely get a bit brighter with the mod but nothing I'd call fatiguing. They are more revealing now so could be highlighting something going on in your chain. Use a different source and see what happens.

 

Thanks Marv. Is there a good source for cheap inner foam discs? Also, any idea what could be causing the slight imbalance? I double checked that all the dynamat cuts were similarly sized between the two channels.

 

My pair had different amounts of back-damping (foam under the 'spider') that once removed led to slight imbalances in the bass and mids. I had to compensate with different damping to achieve the correct balance.

 

Reversed the nickel mod tonight...man what a difference. Its perfect now. I also noticed that I did not have the ear pads properly installed until now. It takes relatively substantial downward force to ensure they are totally seated and making a good seal around the perimeter of the headphone. I had to reach underneath the pad and push the plastic down to make the proper seal. I'm assuming that had something to do with the channel imbalance as its pretty much back to the way it was. The modded 650 is the closest thing I've heard to my wilson speakers (minus the soundstage being out in front). I was a skeptic, but I'm starting to believe.

 

I have no way of knowing if the mods you describe are comparable to the extensive mods done on my Jupiter Audio Research "JAR650." But the resulting sound strikes me as ideally balanced & voiced. Except for missing a few Hz at the very bottom and top, it competes quite nicely with other headphones of mine that cost 5-10X more.

Have been listening to it recently on the Woo WA3. The modded HD650 doesn't require a high impedance source at all. But when one is used, the whole soundfield snaps into focus even more.

I liked the stock HD650 a lot, and this is subtly better in every way that matters.

 

@Pharmaboy

I've been considering trying out a OTL with the 650, and the WA3 was high on the list. How would you describe the OTL sound to someone who has never heard it?

 

Good thread on OTL and other tube topology: https://www.superbestaudiofriends.org/index.php?threads/push-pull-vs-otl-vs-set-tube-amps.3553/

Suggest this thread for more generic questions: https://www.superbestaudiofriends.org/index.php?threads/the-all-purpose-advice-thread.19/

 

I assumed an OTL would be transformative. Instead, it's rather subtle (and all good). With the ZMF Eikon, Aeolus, or JAR650/HD650 mod (all 300 ohm), I hear much the same things:

• Leveling of the whole frequency range. Everything sounds more balanced, calm, controlled. Notes emerge rather than jump out. The effect is greater clarity & focus.
• Dynamics are somewhat different. The Eikon has epic dynamics. On the WA3, it seems slightly less dynamic at 1st--but because of the greater clarity, dynamic impact is still high
• Soundstage becomes more focused: less technicolor & flash, more precision re placement
• And a very pleasing 3D quality to musical notes. They seem tangible.

Of course, some of this may be the effect of tubes vs SS (particularly the 3D note thing). But the rest is at least partly due to corrected impedance matching. It's addictive.

BTW, I got my WA3 with the upgrade 6922 tubes ("Gold Pin Amperex Holland Made NOS"). I love the clean, pure sound, slightly warm but not even close to gooey warmth tubes are often accused of. I'm currently hunting for a type of driver tube said to sound even better.