Maril555, I`d agree with your last statement,I probably would`nt like what you do,nor you what I like.I`m ecstatic with the sound of my system and I hope the same is true for you with your system. Regards, |
Phew !!! For a minuet there I thought It was all getting grumpy and out of hand ;-).
Atma, I appreciate you'r physics based approach to your explanations. Seems to make sense to me.
Charles, I like you're open and philosophical approach to the classification of what will work or not. I think I'm in the same camp as you re trying SET's with these. Probably if there are limitations, the subjective benefits I'd get in the way I listen would more than make up for the downsides.
Personally I have never found the "massive power being better" thing to be true, but there are so many variables here that it is immensely difficult to judge objectively. I'm thinking of a friends class D amps driving his B&W 802's (A horror to my ears). he really loved it, something I couldn't understand.
I am getting a number of truths from this thread:-
1. There are many different ways to get it right. 2. There are more different ways to get it wrong. 3. If we each think that our own system is fantastic then who cares what others think ?? I do like to listen with friends over a nice bottle of wine. But I wouldn't design a system change so they liked it more and me less. (maybe there is a different consideration in the case of designers who are designing products to be attractive to appreciative customers) Actually that's a thought provoking point...... Atmas do you design to what you think sounds great, or is it a case of trying to please some of the people, most of the time ?? I expect in this industry(at this end of the industry) that its driven by passionate artisans who are designing towards their ultimate personal taste. I think that's the only way that you get truly phenomenal products. i.e. someone pushing passionately, for what they believe is the ultimate way to go.
4. The only way to really tell is to experience for yourself in your own room with your own music. Unfortunately this is not always possible so gathering opinions from experienced enthusiasts like yourselves can help avoid making really bad mistakes.
Thanks all. |
Charles1dad - Again you still make false assumptions when you assert that "high powered solid state" may suit someones preferences. The underlying assumption you imply is that high powered solid state has a sound - well that's not true, its going to be speaker dependent. Isn't the primary goal of an amplifier to drive the speaker properly. My point was that you need an amp that is driving the speakers properly and with over 20 years experience with Tannoy 15" drivers in various cabinets, I do believe that many folk incorrectly assume that you only need a few watts because of the high efficiency. I believe that controlling the 15" driver, which has been specifically designed to be phase coherent through the crossover point at 1k, is paramount to maintaining that design intent. I personally do not use high powered solid state. I use a very high current phase coherent 50wpc solid state amp, regarded by many as one of the best solid state amps ever made. I still own tube amps as well, some of which blow the Plinius away completely through the midrange in transparency, liquidity and preservation of harmonics, but are they the best amps for Tannoy - not necessarily. Let me give you an example. A friend of mine has the Coincident Pure Reference speakers which are 94db. He uses most of the time a Bakoon amplifier of 15 watts. This drives the Coincidents in a large room easily. On my Tannoys of similar efficiency the Bakoon sounds very transparent, but runs out of power very quickly, even at low listening levels. As I explained above the efficiency is only half the story and can be misleading. |
Atmas do you design to what you think sounds great, or is it a case of trying to please some of the people, most of the time ?? I expect in this industry(at this end of the industry) that its driven by passionate artisans who are designing towards their ultimate personal taste. I'm looking to improve the performance of the circuit all the time. Until you asked this question, it never occurred to me to try to go for a sound that someone else likes. First off I don't have any idea how I would get into their head to really know what that was :) So I just try to get as much performance as I can, doing it according to the design principles that have guided me now for several decades. To that end: eliminate sources of distortion (some examples of distortion sources are transistors, pentodes and transformers), particularly the kinds of distortion that the human ear finds objectionable. I don't care so much about what distortion if the ear does *not* care, so I do place a value on listening! I go for simple circuits; a lot of people are surprised to learn that our OTLs have a simpler signal path than even SETs have (only one stage of gain). I agree to a certain degree with Charles1dad in that what works for you is fine- that is what works for you. But to that I add that that is in your experience, and what I have found is that no-one has experienced everything. There is always room for improvement. So really its more a matter of if its 'good enough'. One thing that I find interesting is that we audiophiles use much the same language to describe sound ('soundstage', 'relaxed', 'dynamics', etc.) but this language fails to convey the intensity of the experience. So as a result on the Internet two audiophiles can use the exact same expression although one is describing a $600 transistor amp and the other a $50,000 tube amp. Their experience is worlds apart but the language makes it sound like its exactly the same. So we still have to audition stuff- no way around it. Have a good holiday! |
Borg, Nothing at all to get grumpy over.It`s a bit amusing when someone suggests I try PP amps when I used those(several) for 15 years prior to SET awareness just over 3 years ago.Borg I like your list of truths. Regards, |
Atamasphere, I can`t argue with your "so really its more a matter of it`s good enough". Yes that`s true I have`nt experienced 'everything' nor have you or anyone else, it is`nt possible to do . So we`re all left with our individual experiences to guide our decisions(what other option is there?).
It`s easy for me to decide in this sense,I just trust my ears and my gut reaction(emotional response).If I hear something I like better than SET amps I`d change in a heartbeat.It has`nt happened yet(does`nt mean it won`t).All that matters is what sounds best to me (us) and draws me into the music.What OTL does for you,SET does for me. Regards, |
Dover, Come on now, all amplifiers and any component has a 'sound' or signature.There`s no absolute neutral component that I`m aware of.I do agree with what you say is the basic function of an amplifier, drive a speaker load.Ability to drive a speaker does`nt suggest it will also sound good driving it however.Dover you have a lot of experience with the Tannoy speaker and I don`t.My only point is others who are also familiar with it have drawn different conclusions as to what amps work best with it. This is a totally expected outcome,various opinions. Regards, |
Charlesdad Thanks for the response. I think we would agree on most points. Virtually all the posts were recommending low power tubes. If I'm buying an amp for a new pair of speakers, I would try to hear as much as possible of all types of amplifier. Tube amps I have heard extensively and do like are the Air Tight ATM3 monos, Marantz 8B, original Quicksilver 8417's, EAR 519/549's & Futterman OTL1's. |
Dover, I think we do agree on most points especially the advantage of trying different amplifiers if this is possible.Based on the replies in this thread it seems clear a variety of amps would work sucessfully with Borg`s speakers.
Dover you mentioned the Bakoon amp driving the Coincident qiite easily, this does`nt surprise me. My room is 14'x26'x8' and I can completely saturate the room with full scale sound and energy with my 8 watt amp.I`d really like to hear the Bakoon and also the First Watt S.I.T.-1 amp with my speakers. Both are said to be very special. What`s your impression of the Bakoon with appropriate speakers? Is it organic?
Regards, |
The Bakoon I have listened to quite frequently was the SCA7511 with Vishay attenuator. It has a grainless, reasonably transparent sound - very very smooth and easy to listen to. As stated I personally found it underpowered with the Tannoys, but it seems to work well with the Coincindents. I preferred it to the Frankensteins. The Border Patrol 300B also works very well with the Coincidents. |
I love it when we all get along. :-).
Atmas, thanks for the insights into your design aims. Its very nice of you to share them with us.
When my speakers finally arrive (its killing me) I'll experiment and tell you what I liked and why I thought that way. I'll try and see if I can add an demo SET to my auditioned components.....
So in the meanwhile, have a happy Holiday everyone, stay safe and I hope to chat with you early in the new year.
(I'll have to wait for the speakers to burn in first. Daammmmitttt ). |
I had chance to listen TW SE in friends house with Manley 25o old reference monoblocks yestarday.I have TW Royal versions at home with awesome SS amp Sroll Lyric(extremely clean sounding),I was very happy with it.But then i heard tube monoblocks Challenge 833 with 80w Aclass in triode and it was amazing.Since then I am thinking about tubes,many people were telling me,with Tannoys you need tubes and I did not listen.:( Yesterday I heard 20 yers old Manley as metioned above and I never heard such lows in my system,not even with 833's.I wonder,since these Manley"s are very rare to come by in used market,how would manley neo250 or 500 compare with these old beasts 240 ref?Any thoughts?Yesterday's listening experience gave me a big lesson,you don't need precise clean sterile amp to achive the highest goal and that is :MUSIC SHOULD PASS THROUGH THE EMOTIONAL INFORMATION(John Atkinson said that few years ago on this subject)!So I decided to try McIntosh monoblocks 2301.I will bring them for audition on saturday.Manley sound is staying with me till then.Greetings from Czech rep |
The underlying assumption you imply is that high powered solid state has a sound - well that's not true, its going to be speaker dependent. I find the main 'sound' of most transistor amps the is the slight presence of odd-ordered harmonics, which manifests to the human ear as 'brightness'. The human ear is more sensitive to odd ordered harmonics than just about anything else due to the fact that it uses them to determine how loud a sound is. However I do agree that not all speakers work with all amps and there is indeed a speaker dependency! For more on that see http://www.atma-sphere.com/Resources/Paradigms_in_Amplifier_Design.phpMy point was that you need an amp that is driving the speakers properly and with over 20 years experience with Tannoy 15" drivers in various cabinets, I do believe that many folk incorrectly assume that you only need a few watts because of the high efficiency. Agreed. I regard the Tannoy has being moderate efficiency rather than high efficiency. You need some wattage. I believe that controlling the 15" driver, which has been specifically designed to be phase coherent through the crossover point at 1k, is paramount to maintaining that design intent. For this you don't need high power- you need good bass extension out of the amp. In fact the driver in the Tannoy seems to be happier if the amp has a lower damping factor rather than higher, typical of a lot of speakers with efficiencies in the upper 90s or higher. My speakers are 98 db with dual 15" drivers, yet they are easily 'controlled' by a 5-watt amp, even if that 5 watts is really not enough power to satisfy. |
Mikedimitrov, There`s nothing better than hearing something yourself.If would seem a good tube amplifier with the Tannoy is a very good match.I agree with you, an emotional involvement with music is essential. If this vital element is absent what`s the point of listening to music. It you are`nt moved and responding,it`s just a waste of your time. Regards, |
So I heard 2301's and theat was a lot of fun though very expensive.I purchased Neo500,I will report what I think about it when I get it. |
I bought recently the westminister SE and am having the LFD Mistral integrated with ver good results. Adding in the Musical Fidelity tube buffer then having best of both worlds now with ease of solid state stability with that tube sound.
Have tried Bat vk55 mono blocks with vk32 with very disappointing results. The Naim supernait also did not cut it. LFD Mistral ( original old version ) 's clean sounding though only 50 w ( I think so) is sooooo nice.
I am now thinking of getting the Quad combination ... |
Art,I found out TW need high power tube amp,the more the better,shocking results |
Mikedimitrov, I agree TWs do need power, but not necessarily - more better. In my case I've tried most VTLs of that era ('85-'95) - from 100w-500watters. While their Ichibans (EL34s 200w triodes) works superbly, their own 90w (WE 300Bs) kill it, simply sublime. Generally, I'd try avoid classic tubby sounding amps with them, ime - they are much better driven by the more neutral SET/OTL tonality types, and 50w and up are best.
Certain SS amps too could make them sing just as wonderfully though.. Enjoy your TWs! |
gentlemen,
i tried tubes within the BAT vk55 monoblocks 110w pc and all tube vk32 and found that the sound got muggy and dark when playing classical and orchestral pieces. vocals are as usual nice.
i then tried various solid state combos, then vocals sound cold and edgy but complicated classical and orchestral pieces sound nice.
my conclusion - then no single set up for all music generes. i owned (still owining) - besides the tannoy westminister se also : vandersteen quattro + harbeth m30 + tannoy autograph mini all quite different in their type of music style / presentation.
for the westminister se, the best combi i have till date are: LFD mistral with a Musical Fidelity tube buffer front end + anti-cables IC. Speaker cables, i gave up on the anti cables (which would otherwise have been an excellent choice) becos of its difficult hadling ...
Any one tried the quad mono blocks with westminister ... all true british synergy...
rgds |
I use the Art Audio Jota HC monoblocks with my Tannoys. Bi-amping with a quad of Jotas is ideal, but expensive. Also, it took a long time for my Tannoys to break in. Didn't sound good for several months. Now all is glorious. |
Art80342, I've heard that the BAT and the Tannoys are not the best combination. Overall though the speaker is very tube-friendly. |
Gentlemen,
I was wrong about previous judgement on BAT / Tannoy Westminister compatibility!
Changed the Nordost Flatwyre - biwire version out , replacing with normal audio shack grade wires and the sound substantially opened up.
BAT can complement Tannoy! |
Art80342, I have Tannoy Canterbury SE'S and was driving them with an older LFD Mistral, which I still use for my TV setup.It's a nice little integrated. I recently hooked up a pair of de Havilland Aries 845 monos and the difference is shocking.I'm now getting thunderous bass along with a rich midrange and even a more detailed treble than with the LFD.The dynamics are in another league altogether. You should try to get a listen to one of the deHavilland's and see for yourself.Of course, the price differential makes this an unfair comparison. |
To agree with Atma-Sphere, a high damping factor amp is not necessarily the way to go with the Westminster Royal SE.
If you want to get the full bass potential of this speaker you do need the right amp. And with such a glorious, detailed, natural, open bass it is worth getting it right, believe me. I'm not a rocker or a blaster but I won't give up the great bass this speaker is capable of.
I wish the Atma-Sphere MA1 got it all but it does not in the bass. The speaker sounds light with it, and does not go down with realism in the deepest bass. I love Atma-Sphere and Ralph's dedication so this is no slam on either.
I would focus on what works for Westminster owners as that rear loaded folded horn bass presents a different load to the amp than other Tannoys. It's just a different beast.
There's a manufacturer who won't want to be quoted by name but his Westminsters sound powerful, seductive, rich, natural, dynamic, with deep bass, using a CAT amp. I heard classical, drum demo reoords, organ, rock, vocal, jazz and contrary to what an above poster says, you can get it all with one amp on the Westminsters. I am an SET triode guy with extremely efficient speakers but I would try the Westminsters after what I have heard many times at his place but I don't have the room for the Westminsters.
And, I am considering a CAT to replace my SETs. Do a search on the CAT JL2 and you will see other guys who say it sounds like the good parts of SETs but with power and bass drive. |
Very interesting commentaries ... Based on much experience.
I owned Tannoys System DMT 15 MKIIs for about ten years. This is a studio monitor .... While rated at 98db efficient, I found that they sounded best with high current amplifiers. My journey began with George Wright 3.5 single ended 2a3 monoblocks. Wonderful tone, poor timing. Next we're a pair of (Harvey 'Gizmo' Rosenberg recommended) Sun Audio 300b push pull monoblocks with a likely 20 wpc. Those amps were a fine match ... very much a 'classic' sounding combination ... certainly not 'monitorish' sounding.
It was when I was persuaded to follow Tannoy's recommendation of higher powered transistor amps that old assumptions about the superiority of tubes began to be questioned ... at least for these monitors. The Naim 250 was a good match. But my final amp for those Tannoys was designed and manufactured by a small but renouned shop in England called Avondale Audio. I used their 'standard' stereo amp for the last 7 years. It is truely extraordinary sounding, at a moderate price. They also make monoblocks, whose owners totally rave over. Check out their site, and do a search on the Pink Fish audio site in Great Britain.
I recently moved, resulting in the sale of my beloved Tannoys. They've been replaced by refurbished Quad 57s. The Avondale Audio electronics remain.
WTS |
I've heard the CAT amplifiers on several occasions and can understand their appeal (depending on system needs). It's a very accomplished high power push pull amp and offers near universal flexibility for speaker choice. I don't honesty hear much similarities to SET amplifiers. They sound very different to me, this is aclear case of listening preference and system matching. These speakers can sound fine with either type of amp, it really depends on what sound presentation you want . Neither is better than the other, it just a issue of taste. Regards, |
Wow, this thread has taken on a life of its own. Excellent !! I thought I'd drop in to give a quick update on where I am with the power amplifier experiments with WMSE.
1. So I bought the Sophia 300b monos and a new set of tubes ( psvane 6sn7 / Sophia royal princess 300b / RCA 5u4g rectifiers ) all together not cheap. In my system I found this match a little underpowered in the bass. there is plenty of it but its not as controlled or defined as I was hoping. That's not to say that some things don't sound fantastic with them. But its not a combination that I enjoy listening to complex, rhythmic, dynamic music on. having said that solo guitar etc sounds fabulous. I'm keeping these amps they do some things very well. But I need more control so ..
2. I took a risk and bought some (not so cheap)Chinese 845 monoblocs. I was very impressed with the PSvane tubes I'd bought and so I bought a pair of Psvane 845T ref Mono blocs. 2x Two 845's in parallel driven by a 300b and 6sn7 . they are fabulous looking things and they certainly give me more control and better imaging however they are very difficult to match a pre-amp with. The power amps present a 600ohm input load( ridiculously low) to the preamp. My first attempt was with a SS plinius pre-amp I had on hand. This was a fiasco and rendered me an ear bleeding top end and and next to no bass. At this point I am almost crying into my empty bank account. However I have just swapped in my schitt Lyr headphone amp with a set of pre outs on it. This is superior by far. Now I have bass ( thank the hifi gods )- Its still not the most tuneful but at least I know the power amps respond to different pre-amps and can do bass.
I'm interested in trying to get the best out of these amps ( not least because my wife will get the disembowelling cutlass' out if I have to buy more power amps ). I have a friend who has a Cat ultimate mk2 and a Einstein the tube pre-amps and I hope to try these over the next couple of weeks.
In the meanwhile I throw myself open to suggestions as to pre-amps that are good at driving difficult loads. Namely 600ohms. I don't know why they would design a power amp like this. Maybe its because they want to sell their pre-amp that is designed to match. I'd be happy to do that but I don't want to go throwing good money after bad if its not going to improve things.(If you know what I mean).
I'd also like to hear experiences in pre-amp / power amp miss-matches. Has anyone else come across a bassless performance as I describe above and solved it with a preamp switch out. Or should I consign the Chinese power amps to the great transformer graveyard in the sky ??
Yours hopingly, Myron. |
Driving a 600 ohm load is an unusual task for most home audio preamps. We make the only tube preamps that can do it. There are a few solid state units too, but as you found out just because its a transistor unit does not mean it can drive this kind of load.
I think its important for a preamp to be able to drive such a load, but practically speaking it would be a lot easier for you if the amp was modified to have a more traditional input impedance. The way it is set up right now it kind of sounds like there is an expectation that it will be used with professional broadcast/recording studio gear. There is no reason why an amp like this can't have a 100K input impedance, which would increase your options quite a lot. |
Wow, 600 ohms input -- what were they thinking?? Sometimes it's hard to tell whether such a wacky spec is real, or a result of "lost in translation". Based on your experiences, sounds like this one is real.
Preamps that will handle 600 ohms are very rare. I have no experience with Atmasphere's products, but from all indications I've seen, they'd be an excellent choice. Another route (as you learned with your Lyr) is to look for headphone amps with preamp functionality. I'd look for something tubed that doesn't use electrolytic output caps -- which are the typical way that cheap tube headphone amps handle the low impedance loads. I used to have original Eddie Current Zana Deux; it served very nicely as a preamp and had an output impedance of only 16 ohms (no remote, though). |
To be honest though, it doesn't make much sense to go down a route you wouldn't otherwise, just for amps that are WAY off the beaten path. The Atmasphere may be a good option because it'll serve as a top flight preamp whether you stick with these amps or not. |
I'm in a similiar situation as Borg7x9. I have a brand new pair of Tannoy Westminster Royal SE sitting in the other room 'ampless'. I've recently sold (April) my SS amp and not yet replaced it. So, I have a short list: Wavac MD-805m, Audio Note Conquest Silver Signature (low gain), Viva Aurora T (845), LAMM 2.1 and Almarro A340. I am concerned with the power variance between these amplifiers (i.e., 18-55 watts) and my inability to actually hear these combinations. I'm running out of patience with myself leaning one way today, and another tomorrow. It's time to make an informed decision ... with your help. |
Thanks for your ideas gents.
Ralph, financially I like the sound of modifying the input to present a different impedence. Is this a "difficult" thing to achieve ?? I know that's a nasty question given the lack of info.
Would both the mp1 and the mp3 drive this load well ??
I do know a very experienced, local tube guy who repairs/designs amps for the domestic and professional music industry here in NZ. Perhaps I'll get them over on his bench and he can have a look see.
I didn't consider modifying the input as I expected that there was a good reason for 600ohm implementation. Its good news that you think this can be done.
I certainly didn't expect it to have this much impact. I never considered input and output impedance previously. Its opened a whole new area for me :-).
I'm very grateful for your help, as always.
|
Hi Wylmars. Of the amps you mention above I'd love to hear the Viva's . Listening to my 845 based amps (http://www.psvane.com/?Jkg/t845/) .The pictures don't do them justice. I think that when I've nailed the pre-amp issue They'll be fantastic. You could also consider the KR Kronzilla series of amps. I very much empathise with your predicament. Its very frustrating worrying about making the best decision you can. It can easily spoil the experience. If I were to say one thing from my recent experience, I'd say that you need more control for the bass than my 8 watt per channel 300b amp gave me. To get that "high efficency" freedom feeling I seem to need more power. Good luck. I'd been keen to hear your findings as well.
Just one last thing, Jeff Day remarked that the Tannoys are very forgiving of amplifiers and you can get great performance with a wide range. I think he's probably right. |
Wylmars, I think that's a good list of potential amplifiers to use . Since you're seeking suggestions I'd choose the Viva Aurora 845. It's a beautiful sounding amplifier and would drive your Tannoys well. Regards, |
Hi Borg7x9,
Have you looked at VAC preamps? Although it is out of production, the Phi Beta will drive loads as low as 200 ohms, according to its manual. The Signature 2A, which is the basically the same circuit and is still in production, should do the same. Neither are cheap but do come up on the used market. I have a Phi Beta and it is a great piece. Might be worth a quick call to VAC. |
Borg7x9, it should not be that big a deal to change the input impedance of the amp. It may be that it has an input transformer- this is not all that strange in the world of SETs. It might be that the transformer has to be replaced. That is not all that hard- I am sure Lundahl or Jensen makes a suitable transformer.
If the input impedance is set by a resistor it will be a piece of cake!
Our preamps can drive higher impedances with no worries. |
Hi Wrm57, you are right.... looking at their web site the more costly VAC pre-amps recommend an input impedance of >300ohms, which would work for my amps. Thanks for your response. |
Find a Convergent Audio Technology JL2 and be done with it, I heard this combination and it did everything you would want it to. |
Omsed, I may end up doing that. Been contemplating something like that if I'm unhppay at the end of all this . I'd still need a good pre though. thanks. |
Wylmars.I strongly recommend to try mcIntosh tube power amps 2301.Check AudioAficionado forum for reviews.I own these and they are the best amps I have ever heard with Tannoy Westminsters. |
Borg, An amp with a 600 ohm input is designed to be used with a preamp with a transformer output (like professional gear in the old days). Without a matching transformer-output linestage, you can have severe problems with bass response. The amp was probably designed to be used with a specific linestage because transformer coupled gear is not that common these days. |
Hi larryi, What you describe is what I was finding. Almost no bass response. They do a matching 600ohm output linestage. If I cant make other Pre-amps work ( I'm trying the CAT sl1 tonight ) I may end up getting their matching amp. Its not too expensive in the scheme of things.
Thanks for your advice. |
Mikeedimitrov - I hadn't consider a McIntosh. What is it that you believe makes the McIntosh/Tannoy Westminster work so well for you? And are you using a McIntosh pre-amp? |
An amp with a 600 ohm input is designed to be used with a preamp with a transformer output (like professional gear in the old days). FWIW our preamps can drive that load but have a direct-coupled output rather than a transformer. |
I have a capacitor coupled amp that can drive 600 ohms too reasonably well, but, it also is fairly high in gain (18 db) and has a massive 30 uf coupling cap. My friend said that the huge cap is what makes this linestage suitable. |
I spoke to the designer and the 600ohms load input is in fact a transformer not set with a resister. So it would seem that this is a transformer coupled design. I tried a CAT ultimate Mk11 last night (100ohms output) and its very good, transparent, non fatiguing etc but I still don't get the extended bottom octaves. On Patricia Barber modern cool I can follow the Double bass line down to the point where I am missing the lower notes. I Still get the leading edges etc of these notes just not the meat ,depth and scale that I've heard before. The best I've had the bottom end so far is with my 75ohm output pre off my headphone amp. but its too noisy.
Can someone please suggest why their 600ohm matched impedance , tranformer coupled design, might work better than a using a lower impedance pre in a bridged model into the 600ohms as I am trying. I know that matched impedance delivers better power transfer lower reflections but that Bridging delivers better voltage transfer. Maybe I just cant get the differential high enough with the low 600ohm input ??
As you can see I've read enough just to confuse myself. maybe keeping and eye out for an Atmasphere pre is the way to go. It does appeal to me.
Thanks again. |
I don't know about "theory," but, I do know that I like the sound of a number of transformer coupled gear. That is what I am currently running. The "problem" is the limited compatibility of the amp with the transformer input. From experience, I know that if a capacigtor coupled tube linestage is used, it must have a BIG output cap and a pretty robust output (my Emotive Audio Epifania fits that bill, certain Audionote linestages also work at a local dealership which sells transformer coupled amps). Most tube linestages have something like a 2 uf coupling cap and sound thin and totally dead with such amps. Atmasphere says that his directly coupled linestage will work, so you have another fine alternative.
I have not tried solid state linestages which have very low output impedances that could easily meet the supposed at least 10 to 1 impedance ratio that is often bandied about. |
It is the immense size of the coupling cap at the output of many tube preamps that also limits the abilities of said preamp. When you are driving a 600 ohm load, the cap has to be at least 120uf (FWIW 30uf cuts off at 8 hz) in order to not have phase shift problems in the audio passband.
Look at what the output impedance of the preamp is at 20Hz and compare that to the 1000Hz figure and you will see what I mean! If you want the preamp to play bass without coloration, the two figures should be exactly the same.
By the time the cap gets over about 3-5uf, it is offering significant coloration at all frequencies due to inductive effects and increased dissipation factors due to its size.
In the old days, to drive a 600 ohm load with tubes, you needed an an output transformer in the preamp. Of course such transformers have problems of their own. But we developed a patent (we are an OTL manufacturer after all) that allows direct-coupling. Even if driving a 100Kohm load, getting rid of the output coupling cap in the preamp is an easily-heard increase in transparency. |
Just a quick update... I tried an Einstein "the tube" last weekend. It was fantastic. Full, tight bass. Imaging left to right and back to front much better. Its got a 50ohm output impedance. That pre-amp is the best I've heard. Its an option but very expensive new. Now to try and find a transformer coupled design with 600ohm output to see what that does. More findings as I have them. |
05-15-13: Borg7x9 Just a quick update... I tried an Einstein "the tube" last weekend. It was fantastic. Full, tight bass. Imaging left to right and back to front much better. I love Einstein products. When I had my larger system I auditioned their pre and amp. Now that I have downsized a bit I am looking at their integrated. |