[TAZZY9899]

I am running Rm2 speakers with a Mietner pa6i  moded pre , a Bryston 4bst amp, Perpetual p1a/p3a +monolthic ps  with a toshiba 9200 transport and all  LAT cables. I  find my system very accurate and pleasing on very good recordings but bright and fatigueing on average and poor recordings. Alot of my favorite music are not great recordings. I am thinking of adding tubes into my system. What would be a good tube amp to biamp my treble and mids with my speakers. My bryston has 29db gain and I like to play fairly loud. Would I be better off going with a tube pre or maybe all tubes on amplification ..Thanks TAZZ

[warnerwh]

How much room treatment do you have? This alone can help significantly. Also digital equalization can adjust the tone any way you want without any loss of signal quality for a few hundred bucks.  Be sure all first reflection points are damped if possible.  

I get the impression the brightness you speak of is recording/room related.  What concerns me is that if you go with some tube gear the highs will be rolled off on everything. There are many "flavors" of tube gear, some of it sounds like SS gear and some is very syrupy causing mushy bass and what I consider slow sounding.

If you go with something like the Behringer DEQ 2496 you can adjust whatever you want or need to while keeping your same gear.  It's your call as many people love tubes. I've found that a properly set up SS system can be extremely liquid without having the drawbacks of tubes.  

Some recordings are terrible and with the transparency of the RM series speakers you hear all the bad available on the recording. Getting your room in order helps as does digital equalization but I still have cd's that I can only listen to on my computer room system of vintage gear. The vintage gear, Marantz and Dynaco, cover up the horrors of these recordings and make them actually more enjoyable.

[meilankev]

Tazzy,

Welcome to AudioCircle!!!!!

A friend of mine here in Tampa (well, actually, he's about an hour north) owns RM2 speakers (along with Larger Subwoofer and Ribbon Dipoles).  He's been over to my place a couple of times, and I've been to his home twice.  He drives his RM2 speakers with some giganormous solid-state brute of an amp (as well as a solid-state preamp).  The name of his power amp slips my mind, but it is a very-well respected amp.

However, I use both a tube preamp and tube monoblocks to drive my VMPS speakers (RM40s).  After he heard my rig, he was confused how it could sound so much different from his setup - was it the amps or are the RM40s just that much different from the RM2 speakers???  One way to find out would be to "grip it and rip it", so I lugged my preamp and monoblocks over to his house for a lenghty comparo.

To keep this brief, I will go straight to the final verdict (you can find the long version using the search function).  Inserting my tube preamp yielded minimal improvements - far less than I had anticipated, but inserting the tube monoblocks was a huge leap forward sonically.  Yes, this is only one test on one afternoon, so nothing was "proven".  But in that one test, it showed the RM2 speakers can be successfully mated with tube amps and really come to life.

Granted, my tube amps aren't inexpensive, and it may be more difficult to find a moderately-priced tube amp that can control your entire speaker from top-to-bottom in the same fashion.  Therefore, your strategy seems sound to me (if you're trying to keep your costs down).  You already own the Bryston, which is an excellent amp - so continue to use it to drive the bass.  Therefore, you would not need some mega-powerful tube amp in your application, because it will only be taxed with having to drive the mids and highs.

Good luck to you!!!
Kevin

[woodsyi]

I am running Rm2 speakers with a Mietner pa6i  moded pre , a Bryston 4bst amp, Perpetual p1a/p3a +monolthic ps  with a toshiba 9200 transport and all  LAT cables. I  find my system very accurate and pleasing on very good recordings but bright and fatigueing on average and poor recordings. Alot of my favorite music are not great recordings. I am thinking of adding tubes into my system. What would be a good tube amp to biamp my treble and mids with my speakers. My bryston has 29db gain and I like to play fair ...

Hello Tazz,

Warner and Kevin make good points.  You really have to consider all aspects of the system to optimize the sound.  The curse of highend accurate speakers is that it will reveal bad recordings.  Ultimately, there is nothing you can do about bad recordings but I also believe alot of "bad" recording is not due to the album itself but on the playback system's short comings.  VMPS speakers, to my knowledge, have never been accused of playing "soft".  I have tried quite a few pre/amp combo on my RM 40s and have settled on biamping with ss on the woofers and tubes on the ribbons.  I tried passive biamping but I had little sucess due to impedance mismatch on my amps.  I tried a passive attenuator on the tubes to match the levels, but it killed the "sweetness" of the tubes.  I got an active x-over instead.  

If you do passive biamping make sure you get a tube amp that has 29db sensitivity or less if possible.  I say less because I believe you get the best sound out of the ribbons when you open the pots all the way up.  Another alternative is to run your Bryston amp to your woofer through a relatively inexpensive active lowpass with eq that are prevalent now.  The ribbons have complete passive filters -- band pass on the neos and highpass on FST -- and can be run full range from your output on your preamp.  

When you actively biamp (disconnecting the passive coil on the woofers) the ribbons can be driven with a 22 watt push-pull tubes.  I haven't tried any lower but I don't think a tiny SET amp would work with the midrange.  Good luck and let us know how it goes.

[hmen]

I drive my RM2's with a pair of Atma-Sphere M60's. My pre is a BAT VK30i. I find no need to bi-amp.

[woodsyi]

I drive my RM2's with a pair of Atma-Sphere M60's. My pre is a BAT VK30i. I find no need to bi-amp.

There is alway that option if budget permits.  Tazz did not say what his budget is but a sub x-over/eq and a modestly powered tube amp could be a lot less.  

[TAZZY9899]

WELL THANKS first of all for all of your input... finding a tube amp with 29db gain is not as easy as it sounds. Most have much lower gain and many companies do not spec their amps for gain. My pre has 2 pre outs so I would like to go passive.......My questions ..IF!  I can go to a lower gain  tube power amp how much (db gain  ) can the the mid  and treble trim pots povide.. would input sensitivty need to be matched close as well. My buddy is a blue circle nut with vonsweikert vr 4's (I like my speakers better)and his tube seem to soung less harsh but not as dynamic....... he thinks that a tube pre may be the ticket...I dearly love my meitner though......my buddy says to ditch the bryston and buy some sonic power 3's  or another high power tubeamp and go tubes all the way.....  I think would miss the phenominal  bryston bottom end slam, speed  and power ...I work in a maximum prison and after a bad day at the zoo  the bryston gets somewhat abused at times..... ..TAZz

[warnerwh]

Would it be possible to try his amp at your house? That would be your best bet. Most tube amps bass isn't nearly as good as most SS amps. It can be a trade off.  This is part of the fun of this hobby. You will learn what's available and how it works for you. Nobody here will be able to say what you prefer better than you.

[dubravko]

Back in Harmonic Discord VMPS forum days (2001/2002), there was an RM2 user (nick was "john from nj") who had a large collection (I think eleven different pieces) of tube amplifiers and simply loved his older ferrite panels/spiral tweeters RM2s with some of these amps. Maybe you could search through HD forum and try to contact him.

In your case tubes might be just what you are looking for, but I'm sure tubes are not the necessary ingredient for RM2s to sound great on majority of recordings. If we assume that "average" recordings are those issued by major labels, then only a small percentage of them have that "irritating when loud" character. On many of those (recorded from '50s to present) I can listen to acoustic music at levels I measured at live concerts.

To have my RM2 system sound lively and smooth as it sounds now,  there were a couple of major factors. Besides ever most important speakers placement, maybe you need to try to further optimize adjustment of your speakers. I spent quite some time to figure out that in moderately live rooms, it is much better to set tweeter controls to lower position than midrange. On my system, mids are at 11.30 and treble at 9.30 or 9.45. I don't feel any lack of treble. On the contrary, it sounds pretty convincing comparing live sound I have in my head to many recordings I tried. I'd say my room is averagely live, but certainly not too much. It's easy to have a conversation in it even if a couple of people are there and all are talking at the same time. I tried VMPS in rooms which are more like LE-DE rooms, and in those 12.30 position for controls seems much more appropriate. Also, use the lambwool in midrange compartments of a cabinet if your speakers are older than those which have it done at the factory.

Second factor is preamplifier. There is still no guarantee you get the sound you want with the name you buy. Try something else to see how it goes. I tried many preamps, and tubed ones, and was not satisfied until I went to passive resistive attenuation. On the other hand, Trinaural processor I also use between a source and power amplifier seems to be very transparent.

In the end, a bad recording is a bad recording. However, I tend to think that fatiguing character is mostly system and/or room related. In a bad recording, there may be a lack of life or detail or dynamics, or tonal balance may be severely distorted, but only rarely this necessarily transfers into listening fatigue. Most of the times there's just a feeling that recording could be better than it is, but a good music is still great to listen to. However, there are some recordings that I still can't listen louder than some 80 dBA if I don't want my ears screaming for turning volume down...

[baluga]

Hi Tazz,
I just recently upgraded my 2 channel setup from cheap SS kenwood and Denon CD player   to a Reference Jolida 3205 50watt amp with EL34  and Tube CD big improvement to my setup.  My initial goal was to get rid of that fatiguing sound.  

After two weeks with the tube setup I just notice the big improvement of quality of sound but did not get rid of the fatiguing sound.  

Today I adjusted the treble knob at the back of the RM2,  the factory setting is 2:30 o'clock.  My left speaker is somehow set too high to 4:00 o'clock and the rigth set to 2:30.

I turned both down to 1:00 o'clock and viola!  the sound is much pleasing to my ear.  

Try turning the treble setting down you'll be surprised how the sound become soothing to the ear.

btw, my tube setup exposes alot of anomalies in my system, like the HD receiver creates a humming sound but dead quite on the CD player.  

All n all, I'm very hapy with the upgrade.

[James Romeyn]

I highly encourage you to get tubes on the ribbons.  Dual EL34's or any tube amp about 25WPC, plugged directly into the ribbons, will sound great.  If you look you could find one of my Audio Innovations Series 500 amps with input level controls for $300-$600.  I bought mine from the guy who designed/built your speakers.  It is sweet.  

Which tweeters do you have?  Depending on the tweeters I'll advise on level control settings to start.  The point is to have the section (mid or treble) turned up to max that has the least gain, & the other section set accordingly.  Then you must use input level controls on the amp to get final tuning correct.  The most important point is to get the full power of the amp into the section with the least gain.  In that case, 25-50W is plenty of power.

Gain is irrelevant.  If the amp has no input level controls, make some up.  I'll help you if needed.

You gotta do this.  IMO you can equal or more likely exceed the quality of a $10k seperate amp, literally.

I'm doing this now on RM30's & it's the cat's meow, IMO.  I previously did it on the RM2 spirals & RM40.