VTL 7.5 MK II preamplifier

[marty]

Update
Slightly over a month ago, I returned my VTL 7.5 II preamp for upgrading to the 7.5 III. due to some travel (including CES) I haven't been able to report on the sonic changes the upgrade has allowed, but wish to do so now. THe main change sonically from the 7.5II to III is the quality of the bass and midbass. These areas weren't necessarily "soft" as on MOSFET soft, but they were rather, polite. Not now. These areas are strong, taut, and have plenty of punch. From the VTL website:

"The revised power supply is a current-sourced shunt power supply that minimizes impact on the audio signal by eliminating high voltage gain. Far more precise power regulation yields dramatically improved rejection of nNewly available FET technology developed for green technologies such as solar panels and electric cars requiring devices that are normally-on is utilized for the new output stage of the Series III. Unlike MOSFETs that need to be biased on, normally-on FETs operate more like vacuum tubes, using a simpler circuit and conducting current continuously, resulting in a more tube-like sound with greater mid- bass control."

All told, the 7.5 III is a fantastic upgrade and has made the preamplifier even more satisfying.
Marty

 

[JackD201]

I agree with your observations Marty. The III is indeed more solid in its transients and more fluid in its transitions than its predecessor. The unit I heard is fitted with TFK802s'. Do let us know your impressions when you try your Amperex BB's.

 

[marty]

Much to my surprise, I found a NOS pair of TFKN ECC82 to be very, very slightly preferred to my gorgeous TFKN 802S. As you know, the TFKN 802S cost about $1000 per pair. If you know anyone who wants to buy my pair of Amplitron certified 802S for $600, please me know. They have about 200 hours on them (and are good for 10,000 hours). I haven't tried the BB's yet.

 

[mep]

Marty-I have collected 12AU7 type tubes for years and have a tube caddy full of them. I would never pay $600 to $1000 for a pair of them no matter the hype or brand. There are way too many great 12AU7 tubes for a fraction of the price. I have all of the usual suspects: Telefunken, Mullards of all stripes, Brimar, Amperex BB, and every NOS American made version. I like the box plate Mullard military version (CV4003) and the Amperex BB. And the standard Telefunken is no slouch either.

 

[mep]

Marty-I forgot to mention the RCA clear top 12AU7. That tube is a real ass-kicker. Have you tried a pair of those?

 

[mimesis]

Hi,
Can someone provide a live link to the 7.5 III information? Also, what is the upgrade cost from a series II? I am considering acquiring a 7.5II to try.

William

 

[AMP]

William, I sent you a PM on this topic.

For the record, the upgrade makes significant changes to the power supply, output stage FETs, and gain stage topology. Retail cost of the upgrade is reported to be $8000 and is done on an appointment basis. Current wait is approximately 2 months to get scheduled and another 3 - 4 weeks to have the upgrade performed.

 

[Drizmond]

II to III upg

Hi,
Can someone provide a live link to the 7.5 III information? Also, what is the upgrade cost from a series II? I am considering acquiring a 7.5II to try.

William

VTL quoted $8k last year

 

[ML Audio]

VTL quoted $8k last year

Hi everybody,
2 questions please ...

is the new VTL 7.5 preamplifier a full balanced design ? (better to use with XLR ?)
and what about the 6.5 too ?

and then, could you say to me what would be for you the best Transport +DAC to match with a pre VTL ? (for a good sound synergy)
- what about a suite MSB DAC IV + MSB Transport ?
- or Metronome Technology T3a Transport + Metronome Technology C5 or C8 DAC ?

thanks

david

 

[TheAudioAssociation]

Hi everybody,
2 questions please ...

is the new VTL 7.5 preamplifier a full balanced design ? (better to use with XLR ?)
and what about the 6.5 too ?

and then, could you say to me what would be for you the best Transport +DAC to match with a pre VTL ? (for a good sound synergy)
- what about a suite MSB DAC IV + MSB Transport ?
- or Metronome Technology T3a Transport + Metronome Technology C5 or C8 DAC ?

thanks

david

Hi David

Had the 7.5II and used XLR on all inputs. From what I remember it's a fully balanced unit.

Used the Playback Designs MPS-5 with it and it sounded really great! At the time I was using the DAC with my Mac Mini along with a Squeezebox Touch.

 

[ML Audio]

Hi David

Had the 7.5II and used XLR on all inputs. From what I remember it's a fully balanced unit.

Used the Playback Designs MPS-5 with it and it sounded really great! At the time I was using the DAC with my Mac Mini along with a Squeezebox Touch.

Thanks Eddie,

good news for xlr / balanced design !

I've heard good thinks about Playback Designs units indeed ; I'll try to listen to this model.

Other experiences with VTL + MSB or VTL + Metronome ?

 

[AMP]

Hi David,

The 7.5 is definitely fully differential from input to output.

I haven't used any of the DACs that you mention so I can't offer much input there. I can say that the 7.5 is a very neutral piece and will tend to pass whatever character from the source components to the outputs. Changing the two tubes can change the sound of the unit a bit, but it's not a night and day change like you might see in other pieces. I've probably tried 15 - 20 different tubes in mine and always come back to the NOS Mazda CIFTE tubes that Luke and Bea favor. My next favorite are the late 50s / early 60s Radiotechniques.

 

[TheAudioAssociation]

Thanks Eddie,

good news for xlr / balanced design !

I've heard good thinks about Playback Designs units indeed ; I'll try to listen to this model.

Other experiences with VTL + MSB or VTL + Metronome ?

Hi David.... Sorry, no other DAC experiences other than the Playback. I really liked that particular unit based on what I was hearing and didn't audition anything else. So far it's grown some strong roots in my system. MPD3 (DAC only) MPS3 (DAC and redbook player) sounds great as well! You get 85-90% of the big brother at a much lower price point.

 

[Kurt_tank]

My own take is that it is indeed an excellent preamplifier. Its main strength over the Ref 3, which it replaced, is that it was about 3 dB quieter. But, and I say this very hesitatingly because I did not do the proper control experiments, my sense was that the Ref 3 had slightly better deep bass (under 40 Hz) than the Ref 5.

Hey Marty,

Nice review.
I agree that the aforementioned VTL preamps are better, (albeit only slightly, IMHO), than their ARC counterpoints.
(I own the VTL TL 6.5 Signature myself, and I love it.
It is half a step up from my previous preamp, the Ayre K-1xe.
There is a nice sense of image density that the tubes give the music that the Ayre lacked.
And, I too use the ASR Basis Exclusive phono preamp, (the 2010 gold board version), which really seems to mate well with the VTL preamp.
I really am quite satisfied with the preamplification section of my system now!)

Anyway, I do wish to disagree with your one statement though, (shown in quotes above).
My friend and I did a comprehensive comparision between the Ref. 3 and the Ref. 5, (both fully broken in), and the Ref. 5 actually has slightly better, (tighter and deeper), bass response than the Ref. 3. We did a A/B comparison in his system, and while the difference was very slight, it was there nonetheless. They are very, very similar preamps sonically, (and IMHO, whether the Ref. 5 is worth the additional cost versus the Ref. 3 is debatable.)

My two cents worth anyway.
Keep up the good work!

 

[mep]

Some people who have owned the REF 3, REF 5, and REF 5SE say the differences between the REF 5SE over the REF 5 are far greater than the differences between the REF 3 and the REF 5.

 

[microstrip]

Some people who have owned the REF 3, REF 5, and REF 5SE say the differences between the REF 5SE over the REF 5 are far greater than the differences between the REF 3 and the REF 5.

Mark,

I think differently. The difference between the REF3 and REF5 was really large. If your system has bass extension,slam and articulation, the extra bass quality can make a big jump in sound quality. The treble of the REF3 compared to the REF5 lacked purity and air, and the REF5 is also more dynamic. The REF5 SE added mainly scale and more dynamics to the REF5, approaching but being still far from the REF40. All IMHO, using ARC CD players.

 

[mep]

Fransisco-I value your input which is based on experience. I personally have no idea of the differences in the SQ between the 3 preamps because I never owned the REF 3 and REF 5 and I'm only going by what I have read.