Vtl 750

Albertporter

Well-Known Member
Apr 27, 2010
185
19
1,575
Dallas, TX
www.albertporterphoto.com
Are you using 6550's or KT88's Albert and why did you decide to use the tube you did

Steve,

I've only tried 6550 tubes, that's what the factory supplied originally. I use Wing C 6550, the tube originally referred to as Svetlana a number of years ago. Svetlana today is owned by New Sensor and built on the same production line as Sovtek, (new) Mullard, (new) Gold Lion, (new) Tung Sol and Electro Harmonix.

Basically New Sensor bought rights to these names and now markets any tube "brand" you might want. I think Wing C are better than these, the only temptation is Wing C KT 88 and the Shuguang KT 88. The Shuguang KT 88 Treasure are high on my list. I spoke to Grant Fidelity at several shows, the tube is still difficult to obtain in large quantity.

Between my requirement of 50 pieces to just start up my system and $300.00 a pair suggested retail price, this is not a test that will happen anytime soon.
 

Albertporter

Well-Known Member
Apr 27, 2010
185
19
1,575
Dallas, TX
www.albertporterphoto.com
I've done a bit of experimenting with input tubes on the VTL 750 and suspect the results apply to VTL 450 and Siegfried as well. The 12AT7 makes a lot of difference, favorites are Amperex from the early 1960s, pinch waist Phillips and Telefunken diamond bottom.

For 6350, there are only a few choices. Sylvania and RCA are most of what's out there and a rare Telefunken computer tube that for some reason will sub in some VTLs and not others.
 

c1ferrari

Member Sponsor & WBF Founding Member
May 15, 2010
2,162
51
1,770
Probably the standard version, Shuguang Treasure asking price is $7200.00 for minimum quantity to tube up the VTL Siegrfried or VTL 750 (very similar amps).

Wow, Albert! How long between re-tubes? Perhaps, amortized over this interval may make the pursuit/purchase more palatable :)

-Sam
 

Albertporter

Well-Known Member
Apr 27, 2010
185
19
1,575
Dallas, TX
www.albertporterphoto.com
Sam,

I change output tubes at around 1500 - 2000 hours but VTL and SED say they are rated for more.

I prefer keeping tube performance more linear and swapping more frequently. As for input tubes, the Amperex is good for several change outs of power tubes and a good tube tester is the easiest way to check these small signal tubes.

Testing is not an issue for you, I have seen and used your wonderful Amplitrex tester.
 

Brucemck2

Member Sponsor
May 10, 2010
426
102
1,598
Houston area
The 750s are terrific amps. I used them with both big Genesis ribbons and with the big Krell Lat's.

I really appreciated their "liquidity" in triode mode ... they are to most (particularly solid state) amps as a Koetsu Rosewood Signature is to a Grado MM: big gorgeous sound stage, terrific tone, great information density.

What really upset me with those amps was how much improvement was garnered from Silent Running Audio stands and a pair of PS Audio 1000 power regenerators.

The 750s are really the only gear I've ever sold that I routinely wish I'd kept.
 
Last edited:

MylesBAstor

Well-Known Member
Apr 20, 2010
11,236
81
1,725
New York City
The 750s are terrific amps. I used them with both big Genesis ribbons and with the big Krell Lat's.

I really appreciated their "liquidity" in triode mode ... they are to (most, particularly solid state) amps as a Koetsu Rosewood Signature is to a Grado MM: big gorgeous soundstage, fterrific tone, great information density.

What really upset me with those amps was how much improvement was garnered from Silent Running Audio stands and a pair of PS Audio 1000 power regenerators.

The 750s are really the only gear I've ever sold that I routinely wish I'd kept.

I like the term information density! Information density affects so many things: dimensionality, harmonic envelope, etc.

BTW, join the crowd with the SRA VR bases! I ordered the SRA bases from Kevin at the same time as my ART amps so as to make sure they arrived at the same time :) Wished they didn't make that difference but as I said earlier, I think the SRA bases make the biggest improvements under the amps (as compared to the phono or turntable). Of course the latter two sit in my system in a Craz rack as compared to siting the amps on Goldmund cones.
 

Albertporter

Well-Known Member
Apr 27, 2010
185
19
1,575
Dallas, TX
www.albertporterphoto.com
I like the term information density! Information density affects so many things: dimensionality, harmonic envelope, etc.

BTW, join the crowd with the SRA VR bases! I ordered the SRA bases from Kevin at the same time as my ART amps so as to make sure they arrived at the same time :) Wished they didn't make that difference but as I said earlier, I think the SRA bases make the biggest improvements under the amps (as compared to the phono or turntable). Of course the latter two sit in my system in a Craz rack as compared to siting the amps on Goldmund cones.

I guess I should try the SRA then, I've had five different types of isolation devices under my VTL 750 and so far and the winner is Stillpoints component stands. Probably second place was Grand Prix Audio amplifier stands + Apex footers.

Did you compare SRA to either of those?
 

MylesBAstor

Well-Known Member
Apr 20, 2010
11,236
81
1,725
New York City
I guess I should try the SRA then, I've had five different types of isolation devices under my VTL 750 and so far and the winner is Stillpoints component stands. Probably second place was Grand Prix Audio amplifier stands + Apex footers.

Did you compare SRA to either of those?

No but have a close friend who switched to the Stillpoints rack and stands and swears it's the best thing he's done to improve the sound. As far as the carbon fiber goes, and having played with stuff from Avid and Black Diamond Racing, I just feel that this material its own colorations.

The beauty of the SRA is that each piece is designed specifically for that component. Therefore I feel there's less of a chance of intersystem variability-something that esp. concern me with all the accessories and tweaks.
 

Albertporter

Well-Known Member
Apr 27, 2010
185
19
1,575
Dallas, TX
www.albertporterphoto.com
As far as the carbon fiber goes, and having played with stuff from Avid and Black Diamond Racing, I just feel that this material its own colorations.

I'm with you 100% on that, it takes awhile to realize you've traded one problem for another. That happens a lot in high end audio. I think the Stillpoints is an excellent, pretty much no compromise solution and from what you report the SRA must be too.
 

MylesBAstor

Well-Known Member
Apr 20, 2010
11,236
81
1,725
New York City
I'm with you 100% on that, it takes awhile to realize you've traded one problem for another. That happens a lot in high end audio. I think the Stillpoints is an excellent, pretty much no compromise solution and from what you report the SRA must be too.

Actually reread my post and meant Wilson Benesch, not Avid. Had Avid on the mind since just got their new phono stage called the Pulsare. Might even hook it up this weekend.
 

Albertporter

Well-Known Member
Apr 27, 2010
185
19
1,575
Dallas, TX
www.albertporterphoto.com
Actually reread my post and meant Wilson Benesch, not Avid. Had Avid on the mind since just got their new phono stage called the Pulsare. Might even hook it up this weekend.

We both understood, point was carbon fiber is another sonic signature to avoid, at least in my system and appears in yours as well.
 

c1ferrari

Member Sponsor & WBF Founding Member
May 15, 2010
2,162
51
1,770
Hi Albert,

I just picked up a matched quad of 6C33C-B tubes from James Meine and not too soon! I'll check them on the Amplitrex with the sets I'm currently using on the 4 150SE's. I'll need to develop some logic to track all the tubes in the system as well as index the tubes I have new or are currently out of rotation. Any suggestions?:confused:


-Sam
 

Albertporter

Well-Known Member
Apr 27, 2010
185
19
1,575
Dallas, TX
www.albertporterphoto.com
Sam, I think the Amplitrex is an incredible test device, problem is I have not spent enough time reading the book and using it to know how to advise you. There has to be a numerical reading for tubes that provides best possible match for a circuit. Does the manufacturer have a blog where users can trade data?
 

c1ferrari

Member Sponsor & WBF Founding Member
May 15, 2010
2,162
51
1,770
Sam, I think the Amplitrex is an incredible test device, problem is I have not spent enough time reading the book and using it to know how to advise you. There has to be a numerical reading for tubes that provides best possible match for a circuit. Does the manufacturer have a blog where users can trade data?

Hi Albert,

Victor Khomenko and Chris Terraneau/Amplitrex provided elucidating guidance...VERY SUPPORTIVE! :D Now, I need some time to review my data...but that's after I finish reviewing the ET-2 manual! LOL
 

About us

  • What’s Best Forum is THE forum for high end audio, product reviews, advice and sharing experiences on the best of everything else. This is THE place where audiophiles and audio companies discuss vintage, contemporary and new audio products, music servers, music streamers, computer audio, digital-to-analog converters, turntables, phono stages, cartridges, reel-to-reel tape machines, speakers, headphones and tube and solid-state amplification. Founded in 2010 What’s Best Forum invites intelligent and courteous people of all interests and backgrounds to describe and discuss the best of everything. From beginners to life-long hobbyists to industry professionals, we enjoy learning about new things and meeting new people, and participating in spirited debates.

Quick Navigation

User Menu

Steve Williams
Site Founder | Site Owner | Administrator
Ron Resnick
Site Co-Owner | Administrator
Julian (The Fixer)
Website Build | Marketing Managersing