MB 450 Sig issues

[RUR]

OK, VTL wizards, I need your experience and advice...

About a year ago, I purchased a set of ca 2003 i.e. "old" style MB450 sigs to try with my Martin Logans. Since the original tubes were of unknown life expectancy, I immediately retubed with new octets of GL KT88's, NOS 6350 Sylvania Blackplate D-getter and NOS Telefunken ECC81. In extended listening tests vs. a pair of Rogue M150's, I found the Rogues provided a better high end, while the VTL's provided better instrumental separation on large orchestral pieces. In the end, I set the VTL's aside and used the Rogues.

Some months later, a friend with a pair of Soundlab M1's (non-PX) was interested in hearing the VTL's in his system. He's using Bryston 7BSST's (non-squared), with an ARC Ref 3 and Ayre C5XE. In his system driving the Soundlabs, the VTL's simply couldn't cope and the high frequencies were badly distorted. Disappointment all 'round.

Because of some shipping damage, one of the two VTL monoblocks was thoroughly gone thru by VTL when I first received it, so I can't imagine there's anything fundamentally wrong with the amps. Could this be bad tube choice or is it simply a synergy thing? Can't speak to the Soundlabs episode, but I'd heard nothing but great things about VTL+Martin Logan.

 

[cjfrbw]

My impression is that Sound Labs are typically used with custom transformers and OTL tubed amps. Nominally, the impedance is 8 ohms, which should work pretty well with VTL 450, but big electrostats can be finicky.

I had VTL 450's for many years, and thought they were quite good with Apogee Stage speakers. Don't think you can attribute it to the amps until you have tried them with more speakers, you may have a bad sample or not.

 

[microstrip]

RUR, before I move to the MB750s I had the MB450s for some years, also with a Ref3, driving Sound Lab A1s. It was a perfect match, I never had any problem. And sometimes they had to play at high power, as the A1s that I owned at that time were less efficient than the current PX model, and I listen to a lot of symphonic music, including Mahler and Shostakovitch.
BTW, current Sound Lab impedance is around 30 ohms at 50Hz, 4.8 ohm at 600 Hz , 8.5 ohm at 2000Hz and 2 ohm at 20kHz, with great variations in phase along the spectrum. These values depend on settings of the crossover. Not an easy job for many amplifiers!

 

[Theduker]

I have used the MB450 (I had three of them, traded last weekend, plus cash, for Wotans. I miss them very much already! The only way I could part with them is that I had recently purchased a pair of MB300 previously, and that made it bearable... But I realize that selling the 450s was a huge mistake...)

I can say that _they are dead reliable and I had no problems_.

I used them with Magnepans and Martin Logans, for Magnepan I have 20.1 and 2.6, I sold my 3.6 but they were splendid with them as well. My thought was they are more amp than the 2.6 AND the 3.6 needed... Which is a good thing, headroom is good!

When I bought the Magnepan 20.1, Bea Lam told me "finally you have a speaker worthy of your amplifiers". She was right, as usual.

I never had so much as a hiccup from them, _they just work, period_. Also, they run cool for tube amps, tube life is increased...

For Martin Logan, they have powered ReQuests and Ascents. The ReQuest is a very tough load, impedence drops to _half an ohm_ at 20khz. As usual, they performed admirably. I have ARC gear also (vm220 and Classic 150s.) and the VTL performed quite admirably!

I can say that most amplifiers on electrostatic speakers sound like garbage. The VTL is an exception to this! They sound sublime on electrostats and ribbon tweeters/drivers. You will love them.

If the VTL had impedence issues with your speakers, what you need is a set of Paul Speltz's Zero Autoformers... Not a new amp.

Paul speltz is a great guy and he deserves the business, by all means, buy this product.

 

[LL21]

RUR, before I move to the MB750s I had the MB450s for some years, also with a Ref3, driving Sound Lab A1s. It was a perfect match, I never had any problem. And sometimes they had to play at high power, as the A1s that I owned at that time were less efficient than the current PX model, and I listen to a lot of symphonic music, including Mahler and Shostakovitch.
BTW, current Sound Lab impedance is around 30 ohms at 50Hz, 4.8 ohm at 600 Hz , 8.5 ohm at 2000Hz and 2 ohm at 20kHz, with great variations in phase along the spectrum. These values depend on settings of the crossover. Not an easy job for many amplifiers!

Hi Micro...I read your post about Shostakovich and not really understanding it until you can get a system that handle all the intensity without making it sound like instruments shouting and shrieking. What do you recommend as the best cd of Shostakovich, without exception, in terms of the specific piece, specific version by artist and quality of recording and mastering? I heard Shostakovich on an airplane while deciding it was a free opportunity to hear different music without buying. Shostakovich was exactly as you describe and I decided against getting any from that flight...but I am intrigued by your comment about effortless and resolving systems for this kind of music...so would like to give it a second try. Just 1 cd though...the best you can recommend. Thanks!

 

[microstrip]

Hi Micro...I read your post about Shostakovich and not really understanding it until you can get a system that handle all the intensity without making it sound like instruments shouting and shrieking. What do you recommend as the best cd of Shostakovich, without exception, in terms of the specific piece, specific version by artist and quality of recording and mastering? I heard Shostakovich on an airplane while deciding it was a free opportunity to hear different music without buying. Shostakovich was exactly as you describe and I decided against getting any from that flight...but I am intrigued by your comment about effortless and resolving systems for this kind of music...so would like to give it a second try. Just 1 cd though...the best you can recommend. Thanks!

Lloyd,

Some people complain about the quality of the Decca cycle conducted by Haitink, but in an adequate system system and room I always find it exceptionally well recorded.

The third movement of the Symphony No 8 is challenging - the several orchestra string sections must sound powerful, having adequate size and energy, never being modulated by the loud transients. You need a large soundstage to keep all this energy in place without shouting. Bass must be very controlled to support the continuous crescendos.

The finale of the Symphony no 5 is a masterpiece - in a great system you will feel all the power of a symphonic orchestra - if the system is adequate you will want to raise the volume as it never seems too loud. In many systems you will mostly feel the final cymbal stroke, in a great system you feel the whole orchestra.

Symphony no 11, third movement - the viola section of the Concertegebouw Orchestra has an wonderful tone and will define a level and a space. The adagio dynamics is very large, and the volume and dynamics must be respected. And then you should be able to listen to the next movement without touching the volume button!

Although my favorite is the 5th, perhaps for a starter I will take the 8th - it is the most spectacular sounding. Still makes me dream about the TheSonusfaber and the ARC REF750s ...

 

[LL21]

Thank you! I have Haitnick's Shostokovich 8th in Amazon basket! I have heard good things about the 5th and will consider it as well.

 

[LL21]

I spent more time listening on All music, Amazon...have picked up:
- Shostokovich 8th, Haitnick
- Shostokovich 1st, Ormany/Rostropovich Remastered (Which also includes Rostropovich Cello Concerto which is apparently highly regarded)
- Shostokovich 5th/9th, Gergiev

Plenty for now...Thanks for the advice Micro...it was your first advice about systems, resolving and dynamic capability...that got me intrigued to go back and listen again. And your second advice that led me to Haitnick. I also read thru the Penguin Guide and I like Gergiev...so again, many thanks and look forward to listening to these properly.