VTL TL-7.5 series iii

[markramler]

Thank you for your reply.

How would you describe the sonic improvements?

Ron

The upgrades were as follows:

They replaced the gain stage boards where the tubes are mounted with a new and improved version – The new boards use better components that reduced the constant tweeter noise.

They updated the control unit power supply with a new adjustment system for the FET devices, as well as other updates to bring the old power supply as close to the current version as possible.

A complete replacement of the four volume attenuator boards with new production boards that includes new, much more precisely matched relays. These new relays are very quiet and eliminated any of the slight pops that I heard when the VTL is first turned on and the volume steps are adjusted.

Overall, there was an immediate noticeable improvement in sound quality. There is a lower noise floor, a sense of effortless music flow and presence filling a larger soundstage. Clarity and resolution have improved and yet it still sounds tonally correct but more accurate. The Telefunken NOS mid-60s also help to optimize performance.

Mark

 

[Ron Resnick]

Ron

The upgrades were as follows:

They replaced the gain stage boards where the tubes are mounted with a new and improved version – The new boards use better components that reduced the constant tweeter noise.

They updated the control unit power supply with a new adjustment system for the FET devices, as well as other updates to bring the old power supply as close to the current version as possible.

A complete replacement of the four volume attenuator boards with new production boards that includes new, much more precisely matched relays. These new relays are very quiet and eliminated any of the slight pops that I heard when the VTL is first turned on and the volume steps are adjusted.

Overall, there was an immediate noticeable improvement in sound quality. There is a lower noise floor, a sense of effortless music flow and presence filling a larger soundstage. Clarity and resolution have improved and yet it still sounds tonally correct but more accurate. The Telefunken NOS mid-60s also help to optimize performance.

Mark

Thank you very much for this detailed description!

I did request from Brian Berdan and Bea Lamm the 7.5 with the latest updates, so my unit should have the improvements you are enumerating here!

 

[markramler]

Thank you very much for this detailed description!

I did request from Brian Berdan and Bea Lamm the 7.5 with the latest updates, so my unit should have the improvements you are enumerating here!

Your unit will be better as it will also have the new power supply for the control unit.

 

[Ron Resnick]

Your unit will be better as it will also have the new power supply for the control unit.

I don’t know. Different components which are theoretically better does not tell me that I will subjectively prefer the sound of those new components.

 

[Theduker]

They are data cables that control the relays of the VTL 7.5 amplifier. In order to avoid noise and interference the IR remote receiver and preamplifier controller are located at the power supply box. It connects to the tube/FET amplifying box by a the DC power supply cables and two wide connector Centronics cables transmitting just DC signals to control the volume and switching relay coils. All this information is sent in parallel, avoiding any noise due to decoders or digital circuits. In this aspect, the 7.5 is textbook!

I am a new TL 7.5 Series III owner and I am bowled over by the technology and the all around excellence of this preamp.
Of course the sonics are the end goal, but they're here, in my opinion. I am glad, it's the best I've had in my system.
I expected excellence, and I haven't been disappointed. Music simply snapped into focus. My old pre immediately got switched out.
It's more fun to listen!


I had purchased a used TL-6.5 signature a week or so before, which absolutely bowled me over with its build quality. Components, board, casework... Plus, the size is convenient, it fits in a normal sized billy bags rack slot.

I was impressed enough that, without even plugging it in or listening to it, I purchased the TL-7.5 Series III. I am so glad I did.

The TL 6.5 Signature is really great for a single box preamp, it gets toes tapping, and that's one measure of excellence. Lots of trickle down technology from the TL 7.5 Series I. I do believe it is quite deserving of the label "Overachieving". And, there's a Series II that I am sure is better.

The TL 7.5 Series III is even more amazing.

I have to admit, I was a little bored with listening, and I wasn't listening much at all. But the new preamps changed all that, I am listening a lot more now and combing the local thrift stores for Compact Discs, as my winter desert house has only a CD player. But the joy of music is running more strongly than ever.

To clarify a bit of prior information, there are three versions of the TL 7.5- the series I, series II, and series III. I don't believe there are any other rolling updates of any kind. A series III is a series III, I believe, with no variation between them. The series III will say on the power board that it's a series III. These boards are beautiful, a wonder.

If anyone has a Manual for the TL-7.5 Series III, I could use a copy...

 

[markramler]

Thank you for your reply.

How would you describe the sonic improvements?

I am a new TL 7.5 Series III owner and I am bowled over by the technology and the all around excellence of this preamp.
Of course the sonics are the end goal, but they're here, in my opinion. I am glad, it's the best I've had in my system.
I expected excellence, and I haven't been disappointed. Music simply snapped into focus. My old pre immediately got switched out.
It's more fun to listen!


I had purchased a TL-6.5 signature a week or so before, which absolutely bowled me over with its build quality. Components, board, casework... Plus, the size is convenient, it fits in a normal sized billy bags rack slot.

I was impressed enough that, without even plugging it in or listening to it, I purchased the TL-7.5 Series III. I am so glad I did.

The TL 6.5 Signature is really great for a single box preamp, it gets toes tapping, and that's one measure of excellence. Lots of trickle down technology from the TL 7.5 Series I. I do believe it is quite deserving of the label "Overachieving". The TL 7.5 Series III is even more amazing.

To clarify a bit of prior information, there are three versions of the TL 7.5- the series I, series II, and series III. I don't believe there are any other rolling updates of any kind. A series III is a series III, I believe, with no variation between them. The series III will say on the power board that it's a series III. These boards are beautiful, a wonder.

If anyone has a Manual for the TL-7.5 Series III, I could use a copy...

go to https://www.pplaudio.com/documents/TL7_5Manual Series III V 3.1.pdf

 

[microstrip]

that is the exact same combo I was using and the tape hiss was there all the time ( zero tube hiss with the prem16 that preceded it) - I was running Vienna Mahlers - hardly high effciency . The design was to run the 12ax7's at full gain all the time and attenuate from the preamp - as I said BAD design. Sure once you started playing music it was fine - but in between tracks etc , it was a joke for a then 14K so called SOTApre amp. When you live with this day in day out, you realise how bad the design actually is and you cannot live with that.

Only Mark Mikelson had the balls or the ears to mention the tube hiss in his review - everyone else was deaf or on the pay roll.

SoundStage! Equipment Review - VTL TL-7.5 Reference Preamplifier (3/2005)

Luke said use 12au7's which lowered the noise but didn't really sound good or buy a amp with lower gain - around 26db.

My prem16 and ART I bought after the 7.5 were not noisy whatsoever compared to the 7.5. In fact while I was recovering from losing over 50% re-sale on the POS 7.5 - I bought a Cary 98L. great little pre amp and no noise. It was probably more musical than the poorly designed VTL 7.5 as well.

The proof really is Luke finally admitted his design fault when it was changed for subsequent versions of the 7.5 despite telling me it was my choice in amplifiers. as I said, I wouldn't trust Luke Manley as far as I could kick him.

Just some facts. The cj premier 350 has a gain of x53 ( 34dB) , much higher than usual. I could not use it with the ART and had to switch to the ACT2, than sounded extremely quiet but IMHO not as musical as the ART. At that time I talked to Lew Johnson about the situation and he simply told me that the ART was designed for their lower gain tube amplifiers, their more recent preamplifiers had much better signal to noise ratios. The ART had three versions, I upgraded my unit two times. Although the series III was much better than the original it did not make the original a "faulty design" or a "poor design".

I don't want to contradict you, but just want to point that I highly praise Bea and Lew Johnson and consider both serious and knowledge manufacturers - surely both had some less good products along the decades and Bea does not have the hearty and friendly contact of Lew. I still own the premier 350 - I used it with the XLF in very hot days - and surely regret having sold the ART series III, but we can't keep all the great gear we liked. BTW, when I loose too much money selling products I do not kick the manufacturers, I kick myself for having done a poor choice!

 

[microstrip]

Your unit will be better as it will also have the new power supply for the control unit.

Do you know when was it introduced?

 

[markramler]

Do you know when was it introduced?

Upgrades coincide with the increase in price. The 7.5 iii was priced at $20,000 when I purchased it in 2012. I believe upgrades were made around 2015 or 2016 and the price increased to $25k than additional upgrades were made in 2020 when the price increased to $30k.

 

[XV-1]

Just some facts. The cj premier 350 has a gain of x53 ( 34dB) , much higher than usual. I could not use it with the ART and had to switch to the ACT2, than sounded extremely quiet but IMHO not as musical as the ART. At that time I talked to Lew Johnson about the situation and he simply told me that the ART was designed for their lower gain tube amplifiers, their more recent preamplifiers had much better signal to noise ratios. The ART had three versions, I upgraded my unit two times. Although the series III was much better than the original it did not make the original a "faulty design" or a "poor design".

I don't want to contradict you, but just want to point that I highly praise Bea and Lew Johnson and consider both serious and knowledge manufacturers - surely both had some less good products along the decades and Bea does not have the hearty and friendly contact of Lew. I still own the premier 350 - I used it with the XLF in very hot days - and surely regret having sold the ART series III, but we can't keep all the great gear we liked. BTW, when I loose too much money selling products I do not kick the manufacturers, I kick myself for having done a poor choice!

don't worry the first person I kick is myself, however manufacturers need to take some responsibility, especially with their top of range products with worldly claims. Unfortunately the MM review came out after I bought the original 7.5. Having it noisy with any amplifier regardless if gain is high is poor design imo - and why they changed the design is proof of my original complaints - which were ignored at the time.

My cj prem 16, ART and ART III had no issues with tube hiss, nor did the 2k Cart 98L. the ART preamp was never upgraded due to design faults like the VTL 7.5, just better parts and all the teflon caps in the series 3 - the design stayed the same. Personally I thought the GAT was a nice step up from even the ART3, so no regret in selling. I di wish I kept the FM 122 phono stage I once owned - however my system was not good enough for the phono back in those days.

totally agree, LJ is a total gentlemen and helped me a lot with detailed circuit diagrams of then prem8A when my tech needed to fix a blown power resistor as well as sending out the S1 to S2 prem 16 ugrade when cj was not represented in AU for a few years.

cheers

 

[Ron Resnick]

LJ . . . helped me a lot with detailed circuit diagrams of then prem8A when my tech needed to fix a blown power resistor . . .

That was very commendable!

 

[microstrip]

That was very commendable!

For those needing them, the schematics of legacy conrad johnson are available at the conrad johnson owners forum.

Audio Research had a similar policy for a few weeks some years ago, unfortunately they took them from their site before I downloaded all of them ... .

 

[microstrip]

(...) Personally I thought the GAT was a nice step up from even the ART3, so no regret in selling. (...)

You have a good point here - I would not trade my GAT S2 for the ART3. But there was some hidden magic at the two box ART with so many triodes and at that time there were not so many excellent tube preamplifiers around, nostalgia also helps!

 

[tdotson41]

I cannot tell you all how great the 7.5 iii is. Geez the realism is just spot on. The 7.5 iii and the S-400 is match that many amp & preamp combinations just can’t be imho. I’ve had ARC, LAMM and I can honestly say my hears and feet have never been happier.

 

[Ron Resnick]

I’ve had ARC, LAMM and I can honestly say my hears and feet have never been happier.

Which Lamm did you have? On which speakers?

 

[tdotson41]

Which Lamm did you have? On which speakers?

I had the M1.2 and the L2.1 Reference preamp with magnepan 20.7’s.

 

[Ron Resnick]

I had the M1.2 and the L2.1 Reference preamp with magnepan 20.7’s.

Thank you.

And this set-up did not sound totally amazing?

 

[tdotson41]

Thank you.

And this set-up did not sound totally amazing?

It did however I moved to a bigger room and the 120wpc Lamm monos started to lose its grip on the panels.

 

[vkennedy61]

Greetings,
Is there any sonic benefit to disabling unused inputs?

Thanks!

 

[rau]

Looking for some info , I found a 7.5 iii I was intrested in purchasing. After scrolling through some posts on web and here it sounds like it could be needing updates to bring to current specs ? Am I understanding this right