Products

Here is a rundown of any products I have in stock at any given time.  Given the demands of my day job I do not accept orders ahead of time, I just sell what I’ve built.  This also works better with the more experimental nature of what I do as we are always coming up with new designs and/or changing older ones. Feel free to contact me at spritzer@mjolnir-audio.com if you are interested in any item here.  I will reply to every mail so if you haven’t received a reply within 24 hours then feel free to send me another email.  Email gets lost all the time, it is flagged as spam or something like that.  All prices in US dollars (USD).

Now that’s I’ve built a few Carbon CC’s the project has been evolving.  This is meant as a project for those that think the normal Carbon is simply not expensive enough and as a test bed for new tech.  Some things are standard, the chassis used, the amplifier channels for now at least and all signal wire in 99.99% pure, solid core silver.  The transformer is also a massive, fully shielded beast which makes the amp dead silent.  Where I’m experimenting now is with power supplies and attenuator´s.  I’ll list the different amps below which are in stock and what sets them apart.  For now they all use the same high quality power supply which is a version of the golden reference power supply.

This  one features a custom 24 step attenuator with precision resistors.  This one has a much better curve than the DACT equivalent so far more usable range.

Price:  5500$ plus shipping

 

 

Carbon front
Carbon back

It’s finally here, the KGSSHV Carbon.  This is the first electrostatic amp in the world to use SiC FET output devices which are as close to triodes as transistors can get.  The original design concept for this amp was born to tame the rough top end of the SR-009 but it grew from there to become the best solid state amplifier we have designed. Right up there with the BHSE and the T2 as the best amps of their kind all the power you could ever need, a lot of detail, huge and expansive soundstage and the best bass I’ve heard from an electrostatic amp.  Kevin and I are very proud of this one.  Here is the second stage in the KGSSHV Carbon design, a mini Carbon.  Well not quite mini as in the KGSSHV mini but it is certainly smaller.  The Carbon design requires heatsinks which are at least three times the size of the KGSSHV mini so this is about as small as one can go at full power.  In every other aspect this is the same as the larger Carbon.  Same parts used through out and same basic design principle.  It did require a new power supply design so I tweaked the KGSSHV mini design a bit to fit the Carbon better.  Due to this and some supply issues it doesn’t make any sense for me to build both units so I won’t build any more full size Carbon’s and focus on the smaller units.

The silver Carbon is out of stock, only black units left.  Not sure when I will make more of the silver ones due to supply issues.

Price:  4600$ plus shipping 

Carbon Black front
Carbon black back

All new black KGSSHV Carbon.  This has been a long, long time coming and fraught with endless issues but it is finally here.  First batch is only 4 amps and they are a little bit more expensive due to the extra steps needed to make them.  They are now back in stock with no shortage of units.

Price: 4800$ plus shipping

 

I have the mini KGSSHV’s in stock now.  This is a new version with a redesigned power supply.  The basic topology is the same but with a new layout for better thermal performance and more capacitance to improve performance.  Silver front panels on these and with an orange power LED.  Standard mini specs so they run at +/-400V and the current through the output stage is set at 10mA so it runs pretty warm.  It uses the 2SA1968 current sources which gives a more stable circuit with a slightly sweeter tone.

Price: 3000$ plus shipping   

Also available now is the KGSSHV mini in black.  Uses my signature orange power led which looks stunning on the black front panel.  Otherwise these are identical to the silver units.

Price:  3100$ plus shipping

KGST front

KGST back

Now the KGST is finally available again.  This amplifier has been called the mini BHSE and it is a fitting name.  This is a hybrid amplifier and the circuit is similar to the BHSE in many ways.  The power supply is similar and so are the first two amplifying stages.  The main difference is with the tubes used and how they are used.  The KGST uses the tube in a more traditional nature but with the same constant current source as the BHSE.  The tubes used are the 6S4A and they handle the output directly with no extra stages needed.  There are no external heatsinks and the tubes are fully enclosed in the chassis.

Sound wise they are very similar but the KGST is warmer and more forgiving making it a better match to the SR-009.  Like the BHSE it runs very warm so it needs a lot of air to breath.  Similar to the KGSSHV this one has a servo which monitors and corrects the output so warmup is less of an issue.

Price: 3000$ plus shipping

Octave front new transformer
Octave back new transformer

This is a twist on the old all triode design (aka the GES) with some elements from the Sennheiser HEV90 Orpheus thrown in for good measure.  This one is fully balanced from input through to the output but works equally well with RCA inputs through adapters.  Fully regulated power supply and all built on custom circuit boards.

The front end of the amp used a quad of ECC83’s and the output is handled by the trusty old 6S4A.  Brand new input stage means less distortion than the GES ever could muster.  Internally switchable between 117V and 230V.

While building a new batch of these I updated the ones I had in stock with new transformer covers.  People didn’t like the old blue ones so they are now textured black.

Only one of these left now.

Price: 1950$ plus shipping

After extensive testing the second phase of the “cheap” KGSSHV project is ready. So a bit of a back story, I’ve always wanted to make a cheaper amp for people and with electrostatics, that is super tricky.  Schiit gave up and so many amps out there are just overpriced garbage so it is a massive challenge.

Just a few amps in this run but now it has the new power supply and new transformer fitted. I’ve had one of these running 24/7 since early in June with excellent results. This is a KGSSHV in every way but with steps taken to cut costs without sacrificing performance. Basically, it runs at a slightly lower voltage (+/-360V) but is a 2SA1968 KGSSHV through and through. It is a great amp and I’m one step closer to building these in larger numbers to ease the entry to high performance electrostatic sound.

Price: 2300$ plus shipping

People have been asking for years to do some transformer boxes (or energizers) to drive electrostatic headphones and I finally relented. That lot sold out really quickly last year and I finally had time to build some moe.  Over the years I’ve accumulated a large number of SRD-7 transformer boxes, some of which I have converted to pro bias but most have been scrapped. The only things I saved were the transformers and the Stax sockets. So what I did here is to put the excellent SRD-7 transformers into a much better enclosure with my own bias supply to maximize their potential. On top of that the input to the transformers is protected from overload and the output has a clamp circuit so it can never damage the headphones connected to it. This is a fully passive circuit which only kicks in if the transformer peaks at roughly 550Vpp, 1100Vppss.  Any higher than that and you run the risk of damaging Pro bias headphones.

There is nothing here in the signal path except the transformers and the input protection circuitry. The left and right channels are also isolated so issues with using bridged amps. A common ground will turn them into smoke right quick so that is best avoided.

The boxes can be set for either 117V or 230V with an internal switch.  This is one of the many improvements over the first version and why these are a bit more expensive.

Price: 670$ plus shipping

 

Here is something I’ve been working on for a while, the Pure BiPolar or Dynalo Mk2.  The Dynalo circuit has been used in a lot of amps over the years but as parts have been obsolete it was time to finally update it.  The biggest difference is the input stage which is now “super symmetry” as Nelson Pass called it but it means it can take a single ended signal (RCA) and converts it to balanced without any extra circuitry.  That’s why the amp has only one balanced output socket, it is always balanced.  Other changes are higher rail voltages and higher Class A bias for more power.  To power the amplifier modules it has my own version of the ultra stable GRLV (Gold Reference Low Voltage) power supply which is just about the best power supply we can design fed by an oversized transformer.  The end result of this is one of the best dynamic amps we’ve ever designed.  It’s highly transparent and able to cope with even the most demanding loads.

Price: 2100$ plus shipping

This should make some happy, I had some spare boards sitting around and made three new Squarewave amps.  This is a play on an old SinglePower design but with the added benefit of it actually working as it should.  Such a neat feature…  😉  Anyway, these were very well received when I built a batch of them more than a year ago and these are essentially identical except I’ve upgraded a few components as I had ran out of the ones used in the last batch.  It’s a warm and pleasant sounding dynamic amp but with plenty of power for any reasonable load.  Fully discrete design with matched jfet inputs and the rest are all bipolar.  Fully DC coupled as well with a servo on the output to keep it all in check.

Price: 590$ plus shipping

After a lot of requests for an unbalanced dynamic amp I decided to draw up a new version of the classic Dynalo circuit.  This has been my favorite dynamic circuit for well over a decade and today, it’s hard to beat.  It is the basis of the PureBipolar circuit and fully discrete.  Each channel has two pairs of matched complementary Jfet input transistors with bipolar parts for the rest of the way.  This circuit uses the original parts as I managed to find a small stock of them.  Gain is fixed at 7.5 which is a good middle point for most dynamic phones.  The back has a single RCA input with a loop output so the signal can be passed on further down the chain.  Volume attenuation is by a GoldPoint stepped attenuator.

Price:  765$ plus shipping for the stepped attenuator version

Also up for sale is a new version of the Dynalo with the RK27 volume control.  It’s the same as the one above but now the case has been marked on both ends and I’ve switched to the new LSK489/LSJ689 input fets.  Otherwise it is identical.

Price: 655$ plus shipping

 

Page updated 25.11.2017

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