Einstein The Tube users...help

FWIW, the problem you are describing is not unusual for many tube pre-amps. They are only part of the problem. The real problem is the input sensitivity on your amp is too high. What is really nice is to have an pre-amp, like several of the ARC units, which have various gain selections and you can select a 'low gain' setting which gives you better volume attenuator. This little detail isn't going to make your life any easier. :-)

Thanks newbee. I am a newbie (sorry I couldnt resist) to the world of tubes. I guess the input sensitivity of my Pass XA is too high? I am going to check with Pass. BTW, what is a "normal" input sensitivity for a ss amp?

What Newbee means to say is the input sensitivity to your amps is too LOW for your Einstein. Pass would likely suggest that it's just perfect for their preamps, and they would be correct in saying so. The answer is to either buy/make a fixed or stepped attenuator to place between your preamp & amp, or if you are to keep the Einstein, have ITS gain lowered. That is an amazing preamp, one I would certainly keep, and your issue is easily remedied.

Tbooze, FWIW I have read about Pass amps and pre-amps. As a prior owner of one of his Threshold SA amps, one of the finest SS amps I've heard and owned BTW. Several folks thought that Pass amps and Pre-amps sounded best in combo. It may just be that this gain issue was one of their considerations.

FWIW, there are a lot of things which bring the 'matching' gain issues to the surface have to do with folks who buy new and more efficient speakers. Personally I got this experience 15+ years ago when I upgraded some 82db panels which required huge amps to drive to some more efficient, 86db speakers. All of a sudden I had some residual tube hiss from my pre-amp that was very noticible (An ARC SP10 which had not output gain control) and selection of low noise tubes in the line stage became as critical as in the phono stage. I then 'up-graded' to 92db speakers and if I wanted to use the SP10 I'd have to not only pay more attention to tubes, but in order to get a reasonable range out of the volume control I had to put an attenuator between the pre-amp and the amp (10db).

There are a lot of modern high power amps with input sensitivity as high as .5v, many at 1v and 1.5v. Interesting to note that amps primarily designed for use with very high efficiency speakers have input sensitivities upwards from 2.5v. Creates less of an issue for users who don't want to get a new pre-amp or listen to residual noise.

Of course another issue which compounds the sensitivity problem is the input (gain) from the source. For example a 2v output from a CDP is standard now but if it were lower, say 1v or .5v (like Wadia provides) you get a lot more use of the volume control without changing the amp/pre-amp ratio. Ergo, a pre-amp which gives you control over the input gain from a source it can be as valuable to many as a gain selection in its output section (My SP10 has one of these and was very useful when I used MM cartridges with very high output).

Its not rocket science, but its a trap for the unaware. Its just another synergy problem, albeit electrical rather than tonal.:-)

Thanks for the explanation Boa2. I was confused a bit by the lower/higher sensitivity thing. It makes sense that Pass has a low sensitivity (not a lot of input voltage required to drive it to full output). So it seems that the Einstein must have too high an output? I will check about having it adjusted.

BTW, I am also going to audition the BAT VK-51se and it has an output of 50Vrms. Is this too high?

Can someone explain what the preamp output number means?

Thanks Boa2, In self defense, for the anal folks like me, I feel it necessary to editoralize on the issue of input sensitivity numbers and their actual meaning in practice. :-)

While the input sensitivity number is lower it means that the amp can be driven by a lower voltage from the source. What that actually means is its sensitivity is higher than for example if its rated input sensitivity were represented by a higher number. Sounds kinda ass backwards but thats how it works.

Thanks Boa2, In self defense, for the anal folks like me, I feel it necessary to editoralize on the issue of input sensitivity numbers and their actual meaning in practice

No worries. It was obvious you knew exactly what the issue was, and if I wasn't such an "Ernie Einstein", I'd have let it Pass. Boy, I crack myself up! In truth, if not for having had this issue with several components, how it works would still confound me.

Tbooe, in response to your other thread, my suggestion would be to keep the Einstein, and have its gain reduced. It's an incredible preamp, IMO. The issue you're having is simple to fix, and worth the minimal effort. What you will notice when you have the gain correctly matched is a tremendous improvement in the highs, and an overall richening of the music.

If you like, I can send you some cheapie fixed attenuators to use until you get this resolved. Email me privately if you like.

Boa2, I asked and the distributor's initial response is that he does think the factory will reduce the gain. I would have to use fixed attenuators. Does this affect the sound quality at all?

I would have to use fixed attenuators. Does this affect the sound quality at all?

Anything you add to the chain will affect the sound to some degree. However, having recently been in the same predicament, I found that using the stop-gap attenuators that I have affected the sound quality in a positive way, primarily because I was able to raise the volume on the preamp and involve it more in the overall sound. Making fixed attenuators with Eichmann bullets (or the like) is apparently not that hard. Some people like the Rothwells . I've not tried them. Purist and other companies who make adaptors may also make such an item, I'm not certain. The most important part thing is you would want good quality connectors. Again, if you want to try the ones I have, just send me an email with your address.

When I inquired with Lamm about the same issue, they said they could reduce the gain on the preamp for $85. Pretty cheap, huh? Does Einstein have a US service center? Adding a resistor to reduce your gain is an easy job for a good tech, and hopefully won't require you sending the unit to Germany.

all is needed here is a preamp with fine volume steps. Anything over 100 steps will give you a pretty good flexibility. As an aside, volume at 0 on some preamps does not mean volume off. You need to mute it. Such is the case with some ARC units. I had an LS-15 that was like that and now my LS-25 does that too. I wouldn't list it as an issue though. Once you get a preamp with nice volume control(if it has adjustable gain it is a plus) you will be fine.
Personally, I would avoid anything extra in the signal chain between preamp and amp, apart from your existing IC cable of course. No matter how tranparent they say it is.

sure you're using all the right tubes in the einstein?

what's the input impedance & sensitivity of your amp? i know people using 100k input impedance w/ the einstein w/ reasonably sensitive speakers that don't have the problem you describe. i don't have it either, and am using Mac 501s w/ 20k balanced input.

fwiw, i would not add anything in the signal path. the unit is terrific and you should try to avoid altering the signal path (but i also agree, it should be easy for a tech to correct in the einstein)

all is needed here is a preamp with fine volume steps

The issue is one of overall gain, not fine adjustment. As Tboooe states:

When I increase the volume knob just a tiny bit, the volume is VERY loud.

An attenuator is a non-intrusive fix for the problem, one that will still permit the signature of the Einstein to be heard. Having the gain reduced on the Einstein is an even purer solution, especially if you intend to keep it. Based upon your other thread, it sounds like you may be giving up on the Einstein due to the gain issue. If that is the case, you will have never heard what this preamp can do.

Just my two cents, before I drink myself silly tonight...on hot tea.

Boa2, it has to do with gain as well, but if volume control allows for, say, 0.5db increments, this wouldn't be happening. BAT preamps have lots of steps in volume and will most likely be non-issue. So is the ARC Ref-3.

Tboooe, how many volume steps are there on "The Tube"?
What is the output gain of this preamp?
You may want to use this as a guideline for your future preamp. Compare these with ARC Ref-3 specs.

zero should mean just that....

Hey guys, happy new year and thanks for the reponses.

Boa2, I have not yet given up on the Einstein but I am cnnsidering my other options (it is a $14K preamp!!). Though the BAT does offer volume offsets which I like.

Rhyno, I am not sure I understand what you mean by using the right tubes? I just plugged my inputs into the XLR inputs and my output into the XLR outputs. As for my amps, they have 26db gain and an input impedance 22K0hm.

Audphile1, I have no idea about the volume steps. There is very little info about it on the web.

the unit uses 1 12UA7, and 18 of the 6922s. i'd confirm that the tubes spec'd are in there, that you have the problem regardless of source selected, and also if you have it on both RCA and XLR outputs.

the einstein doesn't have volume steps; its a continuous attenuator (not a ladder or shunt)

As for my amps, they have 26db gain and an input impedance 22K0hm.

From the PS Audio website:
"No tube preamp should be asked to drive an input impedance of less than 30K..."

Take it for what it's worth, but I've just gone through the same thing as you are. We all know tube preamps can work with SS amps, and yet yours is in need of a gain reduction, simple as that. If you try out other preamps that do not have gain adjustability, you are likely to encounter the same issue. Thankfully, it's an easy fix.

I drive my X250.5 with 22kohms balanced input impedance with my ARC LS-25 linestage that has 650ohms bal output impedance and 6db(low), 12db(med) and 18db(high) gain.
In medium gain setting which I use, there are no issues with volume.

My suspision is that the Einstein preamp has very limited volume steps and that is what the problem is, along with its relatively high gain of course, which is typical for any tube pre.

I had a tube preamp with 75 volume steps and had the same issue. Once I switched to a preamp with 104 steps, the problem is solved. A Sonic Frontiers preamp I tried in my system had 191 steps and it was the finest volume adjustment, despite its high gain.

My bet is that a preamp with a nice volume control will have no such control issues as too soft->too loud jump in volume.

BAT 51SE has 140 steps in 0.5db increments. Has 17db out gain, which is high, but with 140 steps there should absolutely be no problems with this unit driving the 22kohms amp. ARC REF-3, that has 11.6dB Balanced output gain(relatively low gain for a tube unit) with 104 steps of volum should be no problem either.

Audphile1, excuse me if my posts sounded argumentative. I didn't intend them to be. Mainly, I was concerned that Tboooe might give up on a stellar preamp before hearing it at its best, and admittedly, I've not resolved this issue in the manner you have suggested. Clearly, it will work.

Audphile1 wrote:

My suspision is that the Einstein preamp has very limited volume steps and that is what the problem is, along with its relatively high gain of course, which is typical for any tube pre.

Rhyno wrote:

the einstein doesn't have volume steps; its a continuous attenuator (not a ladder or shunt)

He ought to know. He owns one. Suggestions have been posted in response to your other question.

Boa2, I appologize if I sounded offensive.
Your posts were not argumentative at all. It is very informative to hear about how things integrate in someone else's system.

However, that quote from PS Audio does sound like BS, althouth you did say "take it for what its worth".
:)

Tboooe,

I have been following your post about the Einstein the Tube. Next Friday I am having an at home demonstration with the Einstein The Tube. A product and sales manager from the Einstein factory will be coming to my house to sell me their wares, haha. Living in Germany has its advantages. Anyway, my tube mono amps are rated at 210ohm input impedance which seems like a good range to use the Einstein. My amps can be seen here:
http://www.octave.de/english/products/PowerAmplifiers/INFO-MRE130.htm

If these were sold in the states they would compete in the price range of the Lamm ML1.2 and Mark Levinson ML33's. The manufacture sells these in Japan with 120 volts but not the USA because of some UL requirement that is too restrictive or something, not sure.

How would you describe the sound and especially compared to the BAT or the Aesthetix Callisto if you have demoed those yet? I am still doing my research and have not made a final decision yet. I still have another preamp which is the Callisto. I am interested in the soundstage to include width and depth, dynamics, clarity and naturalness of instruments and voices, that sums up a lot I guess, but I think that is what everyone else wants to know. Thanks.

V/r
Audioquest4life

audioquest4life:

Nice to hear from an audiophile from Germany. You are indeed lucky to have Einstein reps come to your home. As you already know, The Tube is a wonderful looking preamp. It's build quality seems top notce as well. I thought it was very clever that the tubes are all mounted on a spring loaded platform which helps to absorb vibration.

I cannot comment on the soundstaging and imaging as I am having some issues with this because of my room setup. I can comment on the sound however. And thus far, with The Tube, my system never sounded better. I listen to a lot of female vocals and jazz. To me, texture, realism and weight in the midrange is critical. With The Tube, voices sounded incredibly life like, as if I was in the same room with the singer. Instruments also had a sense of realism. I noticed things that I never heard before with my current preamp (Clase CP-700). Its not that The Tube reveled more detail, it just emphasized things that my current pre did not.

One of favorite cds to test midrange is Eva Cassidy's "American Tune". I was amazed at how rich and vibrant her voice sounded. There was a texture that allowed me to actually visualize and feel her vocal chords vibrating as she sang (I know that sounds weird but that is the best way i can describe it).

For bass and highs, I used Bliss' "Quiet Letters" cd. The opening track does a great job of testing the frequency extremes. The Tube handled this with ease. It reached as low as my speakers would go while also making highs sound natural, crisp, and immediate.

As a further test of the highs, I used Stan Getz and Charlie Byrd's "Jazz Samba" cd. I can honestly say, that i neve heard more realistic highs than with The Tube.

Overall, I think The Tube's strength is in its ability to reproduce music in a manner that is lifelike and natural. I did not get a sense of rolloff at either frequency extreme, nor did I hear too much midrange bloom.

Of course, The Tube is not without its issues. Even though the sound is great, it does lack any real features. There is no volume display or volume (gain) adjustment. The standard remote is a cheap looking plastic unit. Make sure you take a look at the optional remote. It really is a work of art but at $700 its way too much. I would prefer to have an output trigger. These may not mean a lot to people but to me, they are important in terms of day to day use.

I hope this helps. Good luck with your audition. I would be curious to know if you have the same volume issues that I did with my maps.

kind regards,

Tboooe,

Thanks for a thorough update in regards to the Einstein.

I spoke with the Einstein factory today and they are going to bring balanced XLR cables to try in my system as well.

It is funny that I am testing a device that costs less than my current preamp, however, is tested and rated as a high-end product in the states. Pricing of this type of equipment plays into our hands tremendously, however, the pricier stuff does not always equal better. I tried the reference preamp from Octave, and man it was nice, great detail, clarity and very quiet, notice something missing, soundstage and width. They were not as good as the HP500SE to my ears at least. The Octave Jubilee sells for about 27K in dollars, 22keuros, and it did not have the soundstage as that of its little brother, hmmm, almost 2 times the price of its little brother preamp, which is no slouch. Well my point, is through our own endeavors, sharing of information and research, we are eventually going to find the right mix of components, no matter what the costs are reasonably speaking. The Aesthetix Callisto is what really I should aim for as it is supposedly a great match with the IO, I will learn that out soon enough, after the Einstein demo next Friday.

Good luck in solving your problem, which BTW I can bring that to the attention of the rep from Einstein and see what his answer is. Hopefully this will not affect me; I currently have 2 gain settings on my preamp, high and low and a volume control with remote control capability. I use the low gain as it is what allows me to get the volume up to about 1030-1130 or so to get decent listening volume. I guess that is the sweet spot because it sounds good. I am also told that using low gain improves signal to noise ratio. Have you ever heard of that?

V/r
Audioquest4life

Hello all,

MR. Bjorn Mertz vom Einstein left my house a short while ago sadly packing the Einstein the Tube with him. I mean that in a good way. You all know we talk about synergy, well the Einstein synergized with my Octave tube amps, the Aesthetix IO Signature phono and the Krell SACD exceptionally well. We used RCA connections for testing from the phono stage and the SACD since I am using that right now at home, to base the comparison on. I use a subwoofer equalized with the Velodyne SMS-1 sub controller to add some sizzle to bass and equal out the room modes, etc.

We conducted the A/B comparison without the sub active to get a fair baseline sample of the character of each preamp. All audio cables stayed the same (mostly Audioquest Sky's) except we ran XLR from the preamp to the mono amps using some (I forgot the name) cable made in Switzerland.

After a cup of coffee and some small talk, we went to the listening room and listened to the Octave preamp with SACD and vinyl source material, I had been running the equipment all morning in advance and in anticipation of the demo.

I told Mr. Merx, that I prefer natural overtones and not the tizzy sound that you get with some pure silver cables or solid state setups. That being said, Mr. Merx was quiet, and we switched the cables to the Einstein, and played the same sources, this time the last source and song played was the first, Chuck Mangione, 200gram Classic reissue, The Children of Sanchez. I look for three things in this song, one the opening lead in when he is singing and it is very melancholic, but the part of the verse he says "and the strength" and you hear a nice reverberation, well this time it was just amazing. It was like he was really in the studio. The next part, there is the lead in when the drums kick in and the flugel horn starts playing, well I just fell out of my seat as the bass was a lot deeper than my other preamp and I thought I had the subwoofer plugged in, remembering that it was not, I was amazed, I looked at Bjorn and said, Nice. So the bass is gut wrenching deep and the holographic effects of a studio are recreated, now the last thing I listen to on this track is the top hat or triangle, there is a triangle solo about 1/2 way into that song and the triangles resonate as it is being hit. I thought before I had it pretty much nailed, but NO, the Einstein grasped the triangle and made it sparkle, making my preamp sound thinner and lacking energy in that frequency spectrum. The energy of the triangles, cymbals and bass were most definitely pronounced. One other thing I noticed that the background noise was even quieter than before, especially with the phono input, the IO does create low level tube rush, and Bjorn stated that the phono was a little noisy, I said, NO, that is quiet compared to what it was, and that there is an adherent amount of tube rush noise in the IO phono stage, however, I can live with it as long as it goes away at normal listening levels and it does and my music sounds good, and it does.

Finally, I was pulling album after album putting the Tube to the test, Muddy Waters (in which we listened to a master recorded version on vinyl recorded by Herr Einstein from the master tapes- don’t ask, but he had the masters to do the recording), the Doobie Brothers, The Eagles, Bill Evans, Sonny Rollins, John Coltrane and each time, the timber was excellent. Additionally, the soundstage gained a tremendous amount of width, clearly the advantage of the true dual mono design. Normally pinpoint and far reaching instruments played through my other preamp, suddenly occupied the whole stage and in a lifelike presentation whereas before, it was more pinpoint, also good mind you, however the Einstein seemed to capture the whole performance on the stage and the presentation was a lot closer and near to you in comparison, my preamp, portrayed the same staging effects and had pinpoint accuracy but with limited spatial cues.

Overall, a very satisfying listening experience in which case it “DID” bring me closer to the musician, literally.

You have to ask yourself, how do they do that? The Einstein sounded very natural used in my system and was neither adding or detracting from the music, it just sounded like great music. I know we all hear the same thing whenever someone gets rolled over by such an experience, but this was my experience and I thought I would share it with you. BTW, heat was never an issue.

Next on the list, is to demo the Callisto. So far, the Einstein has brought me the best joy in music playback than any other preamp I demoed to date. I wonder if anyone has had a chance to demo the Callisto against the Einstein yet?

The volume control and remote worked fine with my amps, however, the remote volume's control seem to be about 1db stepped increase and decreases per click on the remote. Mr. Merz, said he thought it was a normal poti. That is all.

V/r
Audioquest4life

thank you for the detailed review. The Tube really is a great preamp. I hope I can figure out why both of my sources still had issues with the volume.

Tboooe,

You are quite welcome. You still have The Tube? I did not have any gain or volume problems at all hooked up to my system. The IO is set at 62db gain and that worked perfectly with The Tube. Also, my SACD player mated very well with no issues either. The output impedence of The Tube is 84ohms, whereas the output impedence of my current preamp is 100ohms. This is probably why I noted some more top end sparkle with The Tube. My amps are rated at 210ohms input impedence.

My only issue or concern is there is only one set of line level outs, prohibiting me from using the 2nd line out to the subwoofer controller or doing something crazy like bi-amping! The way it is configured I will have to use the tape out to run the subwoofer. Other than that, I am pretty sure I could live with The Tube for a very very long time as it was assimilated into my system with ease.

Ciao,
Audioquest4life

i use an einstein tube preamp into a pair of ATC 150asl active speakers.The einstein has a very low output impedance and has no problem with the low input impedance of the atc,s-but has an output that,s far too high for the ultra -sensitive ATC,s,thus causing the volume control issues mentioned above.I cured the problem with Xlr inline attenuators,connected to the ATC,s amp.inputs-but only after 3 years of messing about.I tried expensive EVS and rothwell attenutors-which cured the gain issue,but restricted the bandwidth (reduced bass and treble).The problem was that the output impedance from the attenuators was to high for the ATC,(output impedance must be below 10% of the input load,which drops down to 1k.ohm on the atc,s inbuilt amps).In the end a pair of $10 microphone -10 db inline xlr attenuators did the trick,as they have an input impedance of 600 ohms-which is Ok for the output of the Einstein,and an output impedance output of 100 ohms which is Ok for the Atc,s built-in amp input impedance.I,m assured that the 3 cheap resistors built into the attenuator have no impact on the sound,which now has fabulous band- width,tone and dynamics,plus a controllable volume. Anyone trying this solution who has a power amp with an input impedance of more than10K ohms (which is normal)would be able to use the EVS 1Kohm fixed xlr attenuators which use expensive vishay silver foil resistors.(however,I,m not convinced these offer any discernable advantages over cheap resistors,as attenuators only use 1 resistor per wire-3 in total per xlr interconnect lead,and,in theory cannot colour the sound,)Remember to connect these to the input of your power anp-rather than preamp,as this reduces your signal-noise ratio,by the attenuated amount.and reduces signal reflections at the end of the interconnects,as mentioned in the einstein product manual .Finally,i,d stick to a -10db. attenuation,rather than a -15 or 20 db,s ,as although it might limit the volume controllability somewhat,it seems to sound better-don,t ask me why!

why not just have a tech add a voltage divider to the +/- pins of the XLR outputs...play w/ values, but you'll shunt some of the output to ground, less output to the amp = more usable range of vol control

Ideally you would build the resistors into the XLR connector,although i wouldn,t know anyone who could do this for me in the UK. I tested 4 different makes of attenuators,3 different levels of attenuation (-10,-15,and -20dbs),and 4 different impedance ratings(of the the attenuators) 200ohm,600ohm.1kohm,and 4kohm. The 600ohm -10db,s proved to be the best,by far,(and the least expensive)for me,because of the very low input impedance of the ATC,s.It would have been a bit of a nightmare to solder in all these variations.And the xlr connectors are pretty well sealed with heat-shrink covers,so,even though i now know the ideal resistor ratings,i wouldn,t be too keen to cut-open the xlr fittings.Also I,m not confident that direct soldering would deliver an audible improvement in sound quality versus seperate attenuators,which are very inexpensive.Maybe the only advantage of being 63 years old is the loss of hearing!