[wuwhere]

I’ll find out soon enough how 007MkI pairs with KGST this weekend. USPS don’t fail me. I had a choice between a KGSSHV mini and KGST. KGST is suppose to be a mini BHSE. I also like the balanced In since my DAC has a balanced out. BTW, I got my KGST from Mjolnir so it’s suppose to be their latest version.

 

[BenF]

Has anyone paired the SR-L700 specifically with either the KGSSHV "cheaper version" $2300, or the KGSSHV-"mini" version $3000, both SS amps I believe, and did they play well together with SR-L700 ? If so, how did either pairing compare to other different amps, please ? Also wonder how close these 2 Mjolnir amps are to each other sonically with Lambdas (L700, others) and since these 2 amps differ running 360 vs 400 volts makes any noticeable audio difference also ? Greatly appreciate if anyone can weigh-in on this, thanks.

Nobody posted L700 with "cheap" and "mini-KGSSHV" amps of Mjolnir yet. Is it because L700 isn't popular or these smaller amps aren't popular?

I did not love the paring of L700 with a premium full sized kgsshv. The kgst or carbon will be a better match. I expect the mini kgsshv would be a very bad match, because it’s bright and works best with the 007. L700 needs tubes or warm SS.

Are you sure? L700 sounds very warm to me on 252S, last thing I'd want to do is to add tubes into the chain.

 

[oneguy]

I prefer the the L700 on the 007ta and T8000 over the 727a. Not sure if it’s due to their use of tubes or other design factors but I suspect it’s due to the tubes. I would also throw my support behind pairing the L700 with tubes.

 

[luvmusik]

@BenF

It may be because not an enormous quantity of L700, KGSSHV-"mini" or "cheaper" versions have yet sold to now. Along with smaller numbers sold, the chance of amp-headphones pairings for both combinations is smaller yet. Our Stax niche is cult-like (we are a gnarly bunch) and maybe not enormous in enthusiast numbers. Maybe in time some impressions will emerge.

Great discussion all around for pure tubes or SS or hybrid tube-SS !

 

[luvmusik]

Just curious...for anyone who has tried L700 with both tube amp and SS amp, could you describe any differences in low frequency characteristics - tightness, impact, timbral accuracy, leading-edge attack of notes, defined note separation of very fast complex passages, any noticeable even-order harmonic reinforcement, or other impressions ?

Especially interested in complicated fast complex compositions - classical, jazz-fusion, prog rock particularly pertaining to low synth bass, electric bass, solo acoustic or electric bass, drumset double-bass drums and lower register orchestral strings, plus instrument separation of these pieces in ensemble figures.

edit:...also, additionally, has anyone heard any noticeable greater "chorale" effect in upper odd order harmonics reinforcement of either chorus voices in classical works or vocal harmonies in other music genres with SS vs tube amps paired again with SR-L700 ?

Thanks in advance.

 

[Blueman2]

I have recently completed a couple of DYI amp builds: KGSSHV Carbon and James Lin's SRX-Plus tube amp. Using both amps with my SR-507's and really love the sound. I am also in the process of completing a Blue Hawaii BJT as well. I am now considering moving up the earspeaker spectrum to either the L700 or 007A. L700 seem to be going for about $1250 these days, and 007A for about $1850, so not a huge premium for the 007A. I listen to a very wide range of music, so no one particular genre I am going for. My initial thought was to go with the 007A since I already have a nice Lambda and wanted to give the Omegas a try. Also, I was worried the L700 was not enough of a jump from the current 507. I really hate that I missed the meet up in SFO this summer, and do not know of anything else coming soon to allow me to audition 007A and L700. Any advice is appreciated.

 

[oneguy]

I feel like the 700 is a big jump over the 507. Well worth the upgrade.

 

[kylev]

Just curious...for anyone who has tried L700 with both tube amp and SS amp, could you describe any differences in low frequency characteristics - tightness, impact, timbral accuracy, leading-edge attack of notes, defined note separation of very fast complex passages, any noticeable even-order harmonic reinforcement, or other impressions ?

Especially interested in complicated fast complex compositions - classical, jazz-fusion, prog rock particularly pertaining to low synth bass, electric bass, solo acoustic or electric bass, drumset double-bass drums and lower register orchestral strings, plus instrument separation of these pieces in ensemble figures.

edit:...also, additionally, has anyone heard any noticeable greater "chorale" effect in upper odd order harmonics reinforcement of either chorus voices in classical works or vocal harmonies in other music genres with SS vs tube amps paired again with SR-L700 ?

Thanks in advance.

Tried my friend's stax setup for L700 with KGSSHV Carbon and BHSE, compared with my SRM-717 Stax amp.
The Carbon (SS amp) immediately shows noticeable difference in terms of soundstage, and amazing instrument separations compare to my 717 amp.
BHSE uniqueness lies on the vocal presentation which is more forward and sweeter compare to the Carbon, but somehow I feel like it is slow sounding, perhaps because of its nature as Tube amp.
Carbon performs very well for complex passages music and my preferred amp for rock music, listen to the Carbon feels like you are listening to live performance due to its massive soundstage.
On top of that it has lesser maintenance, no need for tube rolling and can immediately enjoy it once it is switched on without having to wait long for the tubes to warm up.
If you prefer vocal oriented tracks, then I think BHSE would be your preference.

Just my 2 cents...

 

[AudioThief]

+1
I am considering these 2 amps for my L700 too, would love to hear some impressions.

BenF

Can you give some impressions on L300 vs L700? I am sure you already have, but couldn't find it right now. I love my L300s but yaknow this hobby is addicting so already planning ahead for a L700 purchase if you deem it worth

 

[BenF]

BenF

Can you give some impressions on L300 vs L700? I am sure you already have, but couldn't find it right now. I love my L300s but yaknow this hobby is addicting so already planning ahead for a L700 purchase if you deem it worth

L300 is amazeballs, it is the most transparent headphone I have heard. It also has the largest soundstage - these are called "earspeakers" for a reason.
The bass is laughable though (by TH900MK2/Pro 82 standards).

L700 is so far a huge disappointment to me. It sounds like a very good dynamic headphone, not an e-stat. It doesn't have neither the clarity nor soundstage of L300.
It's too warm, which affects clarity. Soundstage is one of smallest ones I heard in open headphones, even a semi-closed TH900MK2 beats it easily. Much cheaper ATH-AD900X does too.
L700 sounds pretty good, but I just don't enjoy the music - it's lifeless out of 252S.
I don't think it's a problem with lack of power, since both L300 and L700 have the same capacitance, impedance, voltage and sensitivity.
I think I hear a change for the better in 253S, but not 100% sure yet.

L700 responds very well to a tube pre-amp (45$ NS-02E) or a slightly colored DACs (NFB-11.32).
L300 doesn't like either of these, because the coloration takes away it's most prominent feature - clarity. I use it exclusively with Oppo HA-2.
L700 doesn't have that much clarity to sacrifice, but the coloration takes away the boring sound and makes it listenable.
This reminds me of Abyss 1266 - it sounded very good (but super boring) out of Oppo HA-1 (as an amp only), but Cayin HA-1AMk2 made it sound like a best headphone ever.

If you want to experience L700 sound (at least how it sounds out of small amps), you can just buy 003 instead.
With the original tips (no seal) it sounds almost like L300 with L700 pads, except the bass is even more laughable than on L300 with L300 pads.
If you do some tip rolling, and find a good seal, they sound almost identical to L700, except not as boring (with HA-2 and 252S).
I have compared about a dozen different tips last week, but haven't posted the comparison yet - too busy. Hopefully will post in 003 thread later this week.

 

[luvmusik]

Tried my friend's stax setup for L700 with KGSSHV Carbon and BHSE, compared with my SRM-717 Stax amp.
The Carbon (SS amp) immediately shows noticeable difference in terms of soundstage, and amazing instrument separations compare to my 717 amp.
BHSE uniqueness lies on the vocal presentation which is more forward and sweeter compare to the Carbon, but somehow I feel like it is slow sounding, perhaps because of its nature as Tube amp.
Carbon performs very well for complex passages music and my preferred amp for rock music, listen to the Carbon feels like you are listening to live performance due to its massive soundstage.
On top of that it has lesser maintenance, no need for tube rolling and can immediately enjoy it once it is switched on without having to wait long for the tubes to warm up.
If you prefer vocal oriented tracks, then I think BHSE would be your preference.

Just my 2 cents...

@kylev
Thank you for this info. With my SRM-1/MK 2 Pro (SS) and your better SRM-717 (SS), it gives a good baseline what to expect with complex compositions for music listening faves here with your extra testing of Carbon & BHSE. The L-700 have only a couple hours on them now, basically just have had time for a quick test-run to make sure they're fine (bought new). So, have time (maybe years even) to absorb their signature and then advance the amp upward. Who knows, maybe Birgir has more ideas in his future offerings of upcoming amps. I would love & wish for a Carbon (SS), yet used-shape is still too much cost for me. For my fave type music listening (but listen to almost everything additionally), it seems SS may offer better control for the needs, only a guess so far.

Your reply info is important because the new KGSSHV "cheap" version (SS) is per Mjolnir..."this is a KGSSHV in every way but with steps taken to cut costs without sacrificing performance...it runs at a slightly lower voltage (+/- 360V) but is a 2SA1968 KGSSHV through and through". This amp may seem like the best match for my needs pending reviews of it paired with the L700. On HeadCase he also goes on to say the KGSSHV is " ...pretty much dead neutral...".

Regarding the BHSE (thanks for your testing), Spritzer's KGST hybrid tube/SS amp is per his page..."has been called the mini BHSE and it is a fitting name...the circuit is similar to the BHSE in many ways...(much more great info on his site page)...sound wise they are very similar but the KGST is warmer and more forgiving...".

And then the KGSSHV "mini" per him "...a slightly sweeter tone...", assuming this applies to midrange and vocals, guessing. This could also work well here. Sometime will write to him and ask about L700 pairing in my price range for these 3 amps, but can wait for awhile as he is a busy fellow, and time allows the L700 signature to sink in more. I don't have to have lush & rich (but do understand that), definitely don't want the slightest bit sluggish sound portrait and slightly bright is fine for me, but not excessively so. With a very well trained ear for decades in music & exceptionally tested hearing, at near 59 y.o., the age-related loss above 14 KHz is a given. But all that great music under 14 KHz (most of the spectrum) is heard perfectly fine here, so a tad bright shouldn't be any issue.

My speculation is tuff between the 3 amps with projecting impressions from similar types. Will eventually need to get Mjolnir's revered opinion and also until then the rare hope someone had a chance to test A-B-C the L700 with KGSSHV "cheap" version-KGSSHV "mini" version and KGST amps ! Guessing the best synergy of the 3 will remain to be heard if all are tested. So, I am really happy with the gear here & can enjoy it a long time until we all find out more about what's the best match and at or under $3k.

Thanks for your info, the complex music reference is very important to me & SS attributes may make a difference here. Wish to hear all 3 amps ! In time if folks jump on here, we can see some additional feedback regarding these pairings too.

 

[luvmusik]

Currently, still fixed on those 3 amps as a future upgrade - KGSSHV"cheap" version (SS), KGSSHV"mini" version (SS) and maybe KGST (hybrid tube/SS) for SR-L700 (+ other hp models). Prefer SS though and need to keep any new price under $3K, or even less for used.

I almost considered vintage SS non-Stax amps but just learned essential parts may be no longer available if needed for repair ongoing. Then a repair using different parts could change the signature.

To upgrade in the future from SRM-1/MK 2 Pro in SS the Stax upgrades are 727, 717, 353 or other 32X series amps. Feel a larger step upgrade is to go with KG designs if doing this upgrade. Realize some of these KG's sorta were loosely based off of 727 to begin but then greatly changed.

Does anyone know of any other additional amps - SS, <$3K new or less used, above SRM-1/MK 2 Pro, either currently made or discontinued ?

Urgency is not an issue, I can even wait if Mjolnir releases something else new fitting the bill.

Here is the long list of all the estat amp mfrs past or present I can recall; maybe there is something recent (again parts issue) in used-shape that fits the bill. Many of these would not offer a match for my needs (SS) however, are too costly, or are not interchangeable with Stax hps -

Stax & Airbow, Mjolnir & Kevin Gilmore/HeadAmp, HiFiMan, Sonoma, Sennheiser, Woo, Rudistor, Koss, SinglePower, KingSound, McAlister, Masters, Eddie Current, Jecklin, Cavalli and RSA- Ray Samuels Audio. Realize many of these don't apply for the match I need, but it's a fairly comprehensive list of estat amp mfr's. Please post if some other brands are missing.

The few DIY estat amps I've heard about are - ExStata-(Cavalli), Auridux, SRX-Plus, Diablo, Megatron, 300B, Boroskie and must be many more, I dunno. Please post any known names of others (not meaning one-offs, but regularly accepted designs). For me I am most comfortable buying a brand however.

edit : have Illusion (bought here on HF) & Wee also, in storage. Will be some long time to dig them back out & test L700 thru fine loudspeaker amps. Do not have Verto nor Mjolnir energizer. Minor Stax transformers in storage but insignificant.

Any other related advice is cool, too & politely welcome ! Thanks.

 

[organ_donor]

If you enjoy vocals, jazz then KGST suits L700 better in my opinion.

If you listen to mostly EDM, KGSSHV + L700 is lightning fast and much more punchy.

KGST can sound fast too provided you have a bright and a leaner DAC.

KGSSHV has bigger soundstage than KGST if you care about that.

I used to have both KGST & KGSSHV for L700 the same time. In the end i decided to keep my KGST. I listen to almost all genres but sometimes I miss the joys of listening to EDM with KGSSHV.

 

[JimL11]

Here is the long list of all the estat amp mfrs past or present I can recall; maybe there is something recent (again parts issue) in used-shape that fits the bill. Many of these would not offer a match for my needs (SS) however, are too costly, or are not interchangeable with Stax hps -

Stax & Airbow, Mjolnir & Kevin Gilmore/HeadAmp, HiFiMan, Sonoma, Sennheiser, Woo, Rudistor, Koss, SinglePower, KingSound, McAlister, Masters, Eddie Current, Jecklin, Cavalli and RSA- Ray Samuels Audio. Realize many of these don't apply for the match I need, but it's a fairly comprehensive list of estat amp mfr's. Please post if some other brands are missing.

The few DIY estat amps I've heard about are - ExStata-(Cavalli), Auridux, SRX-Plus, Diablo, Megatron, 300B, Boroskie and must be many more, I dunno. Please post any known names of others (not meaning one-offs, but regularly accepted designs). For me I am most comfortable buying a brand however.

So, comments on most of these amps:

HeadAmp - Aristaeus is tube amp, BHSE hybrid solid state with tube outputs, superior circuit design, unmatched workmanship.

HiFiMan - tube amp, mixed reviews sonically (see HF threads), very expensive. See comments below on 300B

Sonoma - solid state, dedicated amp/headphone system, cannot use Stax amps with headphones, cannot use Stax headphones with amp.

Sennheiser - HE-1 hybrid, tube inputs, MOSFET outputs in headphone, dedicated amp/headphone system, not compatible with Stax, very expensive

Woo - tube amps, GES reportedly copied from Gilmore all-triode amp, WES has had mixed reviews, used price in the marketplace doesn't hold up the way BHSE does. Uses choke output loads. I honestly don't see the rationale for choke loading for electrostatic headphones - chokes have relatively low impedance in bass and low midrange frequencies, where much of the power of music is (approximately 50% of the power occurs under 300 Hz or so), whereas electrostatic headphones have their highest impedance at these frequencies. The result is that most of the power is burned up in the chokes rather than being used to drive the headphones. Not to mention the potential for resonances, etc. So less efficient, more distortion at higher cost.

Rudistor - tube amps, reportedly similar to TubeCAD two stage diff design, overpriced for what it is.

Koss - solid state, designed for ESP-950, needs adapter for Stax phones, low current (1 mA) high voltage (600V) design, worse sound compared to Stax SRM-T1

SinglePower - tube amps, overpriced clone of Stax SRX DIY design using EL34 outputs in place of original 6CG7. Combined heater for input and output stages results in poor tube life, also the outputs were biased about 70 volts from ground resulting in less headroom. Supposedly can roll lots of tubes for input stage, unfortunately most tubes lack sufficient gain so the result is a malfunctioning circuit - circuit was designed for 12AT7 tubes and works best with those tubes as inputs. Needs fair amount of rebuilding to function correctly.

KingSound - M10 amp is similar topology to Stax SRM-1 design from 1979 but with FET outputs, tube amp is similar topology to DIY Stax amp A from the 1968.

McAlister - tube amp, reportedly poor workmanship.

Eddie Current Electra - tube amp, EL34 outputs, no longer being built. Reportedly warmer sounding than BHSE. Does not seem to have been a market success.

Jecklin - solid state, higher bias voltage, not compatible with Stax headphones.

Cavilli - solid state or hybrid (tube intermediate stage), out of business, used MOSFET outputs, which are a more capacitative load to drive than the headphones themselves. Mixed reviews on sonics.

RSA - tube amp, apparently out of business, used SRPP output stage, which is a good circuit for resistive loads (e.g. planar headphones), lousy circuit for electrostatic headphones, which are capacitative loads.

Konka Nebuchadnezzar - probably same circuit as the Gilmore all-triode amp but with different input and intermediate stage tubes (6N17P vs 12AX7). Output tubes identical.

Trilogy - tube amp, appears to be same 2 stage diff amp circuit as TubeCAD and Rudistor, passive power supply, overpriced.


DIY:
ExStatA - designed to drive Lambda-level headphones, NOT designed for Omega-level headphones according to its designer.

AuriDux - tube amp, mu follower output, only 10X gain (as opposed to 500-1000X gain for other amps), needs input up to 20 volts, which is the same voltage level as a 50 watt power amplifier puts out. Relatively low output limits - power supply equivalent to +/-200 volts (Stax SRM-T1 is +320/-350 volts). Needs readjustment due to drifting from time to time. Designed to drive Lambda level phones, likely marginal for SR-007.

SRX Plus - modification of Stax SRX DIY design, with current sources to improve differential balance, and current source loads to improve drive capability. Similar quality level to KGST/KGSSHV, able to drive SR-007.

Broskie/TubeCAD -tube amp, variation of the Egmont circuit used by Rudistor, but with clever circuit twist for noise cancellation. Similar drive capability to SRM-T1.
.
Megatron - Gilmore tube amp with solid state current source loads in intermediate stages, clever self-balancing output stage using EL34s. Doubles as small space heater - uses 8 EL34s, which means 80 watts of filament power, not including the filaments for the input tubes.

300B - not sure what circuit is being referred to. However, 300B is best used at relatively low plate voltages (around 300-350 volts) and relatively high currents (40-50 mA) whereas EL-34 based designs (e.g. DIY T2, BHSE, Megatron) use relatively high voltages (400-500 volts) and relatively modest currents (15-20 mA) which are better suited to driving electrostatic headphones IMHO.

Bottom line (IMHO):
In terms of engineering, the best amps are Kevin Gilmore designs and Stax amps (the SRX Plus is a modified Stax DIY design). The other amps out there are either not compatible with Stax headphones, or have shortcomings in design. Most of the DIY designs have marginal current capability to drive the SR-007. The Stax amps are limited in that they have basic passive power supplies, whereas all the Gilmore designs (and the SRX Plus) have regulated supplies of varying sophistication. The choice between the solid state and tube designs is a matter of taste - the solid state designs tend to have better bass and are maintenance free, the tube designs tend to have smoother midrange, and are nearly as reliable as they are designed to drive the tubes conservatively (some Stax SRM-T1s are still using their original tubes 25-30 years after they were built).

 

[paradoxper]

Grab a HV or Carbon. Call it a day. If not, chase the T2. Dream big.