Hattor Audio preamps?

Got my eye on one of these. And yes, my system is passive friendly. I've had resistor based passives before, as well as transformer, autoformer and LDR preamps. So I know I like the sound quality which can be had with a passive. Anyone out there have any experience with the Hattor stuff?



I believe they still offer SMD Vishay, Amtrans AMRT or AMRG, and Takeman REX (carbon) or REY (metal), at least in the Hattor line.  I suggest emailing Arek directly to discuss possibilities for your specific project. 

My first Khozmo passive had Takeman REY resistors and I later gravitated to AMRG resistors in my current Khozmo and two Hattor units. You may also want to look at this video and do some searches on resistors. 

Brilliant - I had a feeling someone here would know! :-)

If I opted for the Khozmo dual-mono passive, what resistor arrangement would you recommend?   It would be paired with my Quad IIs and driving Decware HR-1s from a vinyl source. Rplacing the existing Audio Synthesis Passion Ultimate (passive Pre).

I'm more about musicality and soundstaging than clinical detail.

Many thanks!


"- is there a simple answer?"

Sort of. Two companies run by the same guy (Arek Kallas) from Warsaw Poland, offering a couple of different types of discrete resistor volume controls, but Hattor has the more upscale, complex products with better looking casework while Khozmo offers more simplistic solutions, at lower prices, in more basic looking casework.

Because Arek will customize the builds from either company, you really can have it your way. I use a Khozmo volume control in my main system, but it is made from two separate volume controls (i.e., dual mono operation), has a display and full remote control of L/R volume and mute, plus on/off and display illumination. The attenuators are Hattor/Khozmo’s best using Amtrans AMRG resistors. It is in a Khozmo metal/wood case and has no switching, only a single balanced input and a single balanced output with Furutech connectors.

So, it is a very well made Khozmo badged unit but also very simplistic and in modest but nice-looking casework. The sole purpose is to passively control the volume ahead of a unity-gain, solid-state buffer that feeds my amps, and to allow me to remotely operate volume/balance/mute for my system and to see the result on an easy-to-read display. I also own two Hatter "The Big" preamps, which are very nice sounding units with much more functionality than my Khozmo by providing various single-ended and balanced inputs and outputs, and both passive or active operation with switchable gain from 3 to 9 dB. I used to own their Tube Buffer, which was very nice sounding as well.

Hi   I'm confused as to the differences between the Khozmo and Hattor passive peamps - is there a simple answer? :-)


I own 3 of his KHOZMO DUAL MONO and I own 2 of his HATTOR WITH ACTIVE AND PASSIVE CHASSIS HE CALLS IT the big HATTOR preamp with the full on best packages on both active and passive….I Took it one giant step forward  and replaced all the capacitors in the active with DUELUND and I really cannot express in words the level I’m at now ….the 25K level…..that’s all ill  say…..you will have to raise the roof on the active to accommodate the duelunds but it’s easy just get longer screws and spacers and you don’t even notice it when on shelf….TELEFUNKEN TUBES ARE AWESOME IN IT ALSO…IF YOU DONT feel,like raising the roof the next best musically is the V-caps CuTF CAPS THEY JUST TAKE LONGER to break in if you don’t believe duelund or v- cap are the best ….well….. that’s ok …..

I loved my Hattor passive The Big (dual mono), but sold it as I got a great deal on a Audio Alchemy DDP -1, dac/pre (see Absolute Sound review (March 2016. Later I purchased the optional PS 5 outboard PZ which is an amazing addition

FYI: Hattor offers a input board for it

No apology necessary.  Just wanted you to understand that what I hear in my system could be very different than what somebody hears in a system using low-powered tube amps with high efficiency speakers. 

Oh my goodness. Apologies @mitch2. This entire time while reading this thread I had you mixed up with another member who has a somewhat similar user name, but was helpful when discussing Aric Audio and Tannoys in a private conversation many months ago. @ozzy62 thank you for the candid response. Very helpful!


"I know you and @mitch2 have Aric Audio amps and Hattor preamps"

@ozzy62 has Aric Audio amps but not me.  I have a pair of 650wpc monoblocks made by SMc Audio using formerly McCormack DNA-1 amps as a starting point.  Actually, I believe the only parts used from the DNA-1s were the chassis and heatsinks!  Mine are the black pair at the bottom of the first grouping of pictures on the home page.  

Although my custom built Khozmo volume controller is passive, I send the signal thorugh a unity gain buffer based on SMc's VRE-1 preamp circuit.  My system is basically the opposite of Ozzy's system that uses high sensitivity speakers and tube amps.


I did own one of Don’s preamps and it was very good. I sold it when I went to an Allnic integrated amp. When I decided to go back to separates I thought I’d try the Hattor and I’m glad I did, it’s a great pre. I’ve owned many active and passive line stages and I always come back to passive because I favor high sensitivity speakers and tube amps, which is where they shine. I honestly think if your system is passive friendly, there aren’t many actives that can sound better. Again, that’s my opinion.

Ive owned them all. TVC, AVC, LDR and resistor passives. All are good and will beat most actives in the right circumstances.

@ozzy62 earlier in the thread you had mentioned that you had a Don Sachs preamp; I've only heard good things about Don Sachs. I know you and @mitch2 have Aric Audio amps and Hattor preamps, but was curious if you had tried Aric's preamps. I'm a little torn between Don Sach's, Aric Audio, and Hattor for a preamp which would be matched with a Aric Audio Transcend Push Pull (preamp bypassed). Regardless of the answer, this thread has been extremely informative. 

I don’t now why the normal rules wouldn’t apply - passives work best being fed a low input impedance signal (<200’ish ohms) then output to a high impedance amplifier input (>50K ohms) and being positioned so the output IC only needs to travel a short distance to the amplifier (<1.5M).

Even if you meet those guidelines, some (but not all) still find their passives lacking in tonal body and drive that active stages seem to provide.  The only passives I didn’t have that issue with were AVC types.

Hello everyone... I have very little experience with passive preamps... I only had a Promitheus whose sound was good but the built quality was mediocre... (RCA jacks were too small)... recently I started a conversation on audiogon in order to find a preamp that would be a good match for a GaN-Fet amp... I wonder if a passive preamp would be a good match with such an amp... anyone has experienced this combination ?


In a different thread you asked about Hattor's Tube Active Stage and I said I would answer here in this current thread.  I have cut/pasted and slightly edited portions of a couple of my previous posts that I believe will answer your questions about the Tube Active Stage:

Active Buffers

The functional purpose of an active buffer is to improve impedance mismatches by reducing higher impedance inputs to lower impedance outputs.  This can be helpful when driving amplifiers with low input impedances, when using passive volume controls that do not actively buffer the signal, and/or when driving long interconnects.  The effect can be significant, even in cases of unity gain (i.e., no net voltage gain between input and output), and the change in sound is sometimes described as having more body, tonal color, and drive.   Active buffers can be either fully solid state or tubed.

Tube Active Stage

I use the Hattor Audio Big preamp in passive mode to control the volume of my system and it sounds significantly better to me when followed by my SMc Audio buffer (solid state and unity gain) that is based on their VRE-1 preamp.  I also have the Hattor Audio Tube Active Stage, which is a tube buffer that typically comes with 9dB gain (mine has 6dB).  It is basically a tube buffer stage without a volume control. I have tried the Tortuga Tube Buffer on one of their tours, so I had it in my system for about a week, and I also tried the Purity Audio tubed buffer in my system. 

IMO, and in my system, the Hattor Tube Active Stage sounds very good although it just doesn't provide quite the magic of my SMc Audio TLC Signature buffer, so it is currently sitting in a box.  However, if I didn't have the SMc buffer, I would be perfectly happy to substitute the Hattor after my passive volume control.  

The Hattor Big preamp also comes with an opamp active stage (mine has the NewClassD discrete opamp stage), which can be set to 3/6/9 dB gain.  I bypass the active stage to run the Hattor as a passive into the SMc buffer.   However, I have tried it through the discrete opamp stage and I also find that to be an improvement over running it passively.  Therefore, in ranking buffers (some with low gain) in my system, I would put the solid state SMc Audio buffer first and the Hattor Tube Active Stage second, both of which I would be happy to use.  Third would be the discrete NewClassD opamp stage in the Hattor Big preamp, which I would judge as just a small step below the first two, although others may reverse the order and prefer the opamp stage over the tubed stage - they are close.  Finally, I just did not like the sound of the Tortuga or the Purity Audio buffers in my system.

and, more thoughts...

As I remember it, I was impressed with the sound through the internal NewClassD op-amp active stage of Hattor’s The Big Preamp. The drive, dynamics, and clarity were very good.  My recollection is that I could live with either the tube stage or the internal op-amp stage. 

Talking with Arek he suggested the AMRG to me. His words were they were more musical. This was in response to wanting more "body or warmth" in the setup. 

Earlier this year, I owned the icOn 4PRO AVC balanced passive preamplifier that uses four Slagle autoformer volume control modules. It was seductive in how the music was presented with the warmth described by @ozzy62 coming from a dead quiet background. I really enjoyed listening to it, and the Django TVC, if at all similar, may be just the thing for you. Ultimately, I slightly preferred my Khozmo volume control/SMc Audio TLC Signature Buffer slightly better, so I sold the icOn AVC unit.

I have not spoken with Arek since earlier this year and I am a bit surprised to hear he would recommend the AMRT resistors over the AMRG version. Both are carbon film but the AMRG appears to be Amtrans Corp’s more upscale version based on their higher pricing, gold-plated OFC lead wire, and description as "High-end carbon resistor." The AMRG resistors sound better to me than the Takman REY metal film resisters I had in an earlier Khozmo passive volume control. I have not heard the Takman REX or AMRT resistors. I suggest doing some research and talking with Arek before deciding on resistors.

I own the totl Luminous Audio, 3 in, 2 out, single ended, with remote volume, and it has been the most neutral of all passives I have tried, including many of those mentioned above. My best, MrD.

I had the Hattor Big passive, and loved it, but got a great deal on Audio Alchemy DDP-1 + PS 5, which includes a very good dac, so I sold the Hattor

I have owned most every type of passive device. In my opinion, a TVC is the warmest of all. I wouldn’t say it has more body, but definitely a warmer sound while still retaining the transparency of a passive. TVCs aren’t quite as transparent as an LDR or resistor based passive.

The Hattor is the first resistor passive I have liked. Mine has the AMRT resistors from AMT Trans. Similar to the AMRG but according to Arek, even better. I am pairing it with an Aric Super 300B amplifier and the result is to my liking. I feel like I get all the goodness of the 300B tube with incredible transparency.

The Hattor Audio Big passive is a stone cold bargain IMHO.



I appreciate the replies!

My current situation:

I have a new 3 stage 300b amp from Radu Tarta. It is amazing! The catch is that it doesn't need my Radu 26 DHT preamp infront of it. So I'm looking at going the passive route. I currently have a Luminous Audio Axiom w/ Walker mods on loan from an audio buddy. It's great! With the exception that I miss the body that the DHT preamp adds to the system. The Axiom for lack of better terms sound detailed and quick but that midrange warmth is tough to lose. 

I have a Django TVC that will be here Monday and I've been talking with Arek about a Khozmo withers the AMRG and the opamp added so I can have the gain if needed down the road. 


My question is will I get more body to the sound with the TVC or the higher end Khozmo? I love all of the positives that come with the Axiom though. 


Not sure how I responded to the wrong member but my post below from earlier today was intended for you.  Hattor’s The Big Preamp is a very good sounding preamp and a great value.  Let us know if you have any specific questions.


I still own two of the Big Preamps and more recently had Arek make a custom Khozmo dual-mono passive using his best Amtrans AMRG resistors and volume control from the Hattor, upgraded connectors, and only a single input and output (i.e., no switching) that I use to remote control the volume and provide a display into my solid state, unity-gain buffer.

The Big Preamp is IMO hard to beat for the money and for what you get wrt the volume control, remote, display, balance, connectivity (RCA and XLR), flexibility (i.e., passive vs. active with variable/switchable gain), and of course sound quality.  I also owned the Hattor Tube Active Stage, which is quite nice as an option to their op-amp active stage (my Hattor preamps have the NewClassD op-amps).

Do you have specific questions?

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I just wanted to update this thread. I received my preamp about a week after ordering it. Working with Arek was a pleasure. It is extremely well constructed and solid. When you factor in the quality build and the flight case it ships in, you can understand he’s not getting rich at this.

It is very transparent as you might expect, but dynamic as hell too. Just gets out of the way and let’s your amp do it’s thing, which is exactly what I wanted. Highly recommended.

I had the Big and loved it. Wish I could have kept it for some future need, but needed the money to help fund its replacement

I placed my order today with Arek for his "big" preamp with the AMRT resistors. He says it should ship next week. Stay tuned.



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I keep tellimg my brother to get one of these ... the remote with digital display

The impedance issue can be more involved than simply verifying a 1:10 ratio (which many consider a minimum with a more desirable number being 1:20 or higher).  For example, many preamps (and particularly tubed preamps) have output impedance that is significantly higher at frequency extremes (particularly at bass frequencies) than at 1K Hz which is the typical frequency where the output impedance is reported.  In those cases, the reported output impedance (i.e., at 1K ohms) can result in one ratio while the actual ratio at frequency extremes could be much different (i.e., lower).  JA at Stereophile used to regularly report about this in his measurements of (mostly tubed) preamps.  Below is an example from his review of the Lamm LL2 Deluxe:

The LL2's output impedance was a low 245 ohms in the midrange and treble, this rising to 3.3k ohms at 20Hz, presumably due to the finite size of the output coupling capacitor. As a result, the preamp's frequency response suffered from a premature low-frequency rolloff into the low 600-ohm load (fig.1, lower pair of traces). Into the higher 100k-ohm load (fig.1, top traces), the response is flat from 10Hz to 50kHz and just 1dB down at 200kHz. 

It also becomes important with passive volume controls (i.e., passive linestage) where the output impedance is dependent on the impedance value of the volume control, and where the IC cable impedance becomes more important without active circuitry (which is why most recommend very short cables when using passives).  

Regardless of what Paul says in the video, there are still solid state amplifiers with input impedance as low as 10K ohms.  This is rarely a problem when using active solid state preamps, which typically have output impedances in the range of 100-200K ohms, or lower.  However, amplifiers having low input impedances will not likely reach their full sonic potential when driven through a passive line stage.  For this reason, the sonic impact of using a buffer (i.e., active circuitry to address output impedance) between a passive preamp and an amplifier can vary significantly depending on the differences in input impedance between amplifiers.

@curiousjim ,

So, the preamp should have at least 10 times the impedance of the amp?

Terrific, thank you!

I have exchanged several emails with Arek over the last two weeks. He is very responsive and I have no doubt the transaction will be seamless.



I purchased a Khozmo preamp a few months ago.  I had been using a 12AU7 tube buffer.  I did not like the volume control.  Not linear but sound was good.  I bought the Khozmo to keep the cost down(vs Hattor)  I have upgraded resistors.  The build quality is superb.  Aesthetically, this is a unique and nice looking piece.  Sound is transparent.  Their equipment is customizable with the intent of unaltered sound.

Arek is very easy to deal with. I emailed Arek and hoped everything was OK in Poland.  He is housing a Ukrainian mom and her child.  What a noble gesture.

I do not own the Hattor but own Arek's Khozmo passive. Excellent passive but definitely prefer the Dave Slagle autofomers!

I've used a Khozmo volume control/ "preamp" for several years now in two different iterations, and I would be hard pressed to go back to an active preamp despite having owned a few excellent ones through the years.  Sonically, it's about as transparent as you can get and is the embodiment of simplicity.  Build quality is top notch, and customer service from Arak (despite being in Poland) has been exemplary.  My highest recommendation.

the higher the input impedance of the power amplifier, the better, the minimum from which I would probably be interested in passives is 50k

Can someone give me the rundown again as to the rule of impedance compatibility?


I have one that’s got all the upgrades and the tube stage as well. It’s a superb preamp for sure.  In my system, the tube stage adds a lot to the sound being amazing.  I recently compared to the Benchmark and there was no comparison, the Hattor is worlds better.  This piece oozes quality and sounds incredible.