Active Preamps vs. TVCs again

johnfromnorwich

johnfromnorwich

Tannerd.
Joined
Dec 8, 2005
Messages
276
Reaction score
0
Okay - so I've had a (Glasshouse) TVC for six months or so but I got the chance to run a comparison with a WAD Pre2 the other night and was mighty impressed with the WAD - very good bass control, substantially wider stereo image and a very dynamic sound - Tony Williams' drumming on Miles Davis / Sorcerer sounded just colossal. However, it was only a couple of tunes and we were also using a Phono2 in place of my Dino - so I was probably getting a bit extra zing from the record player.

Somewhere on this forum, Dik Dolan suggested that the Pre3 and Glasshouse TVC sounded very similar to his ears but did comment that the Pre3 had more boogie (I guess this is what I was hearing to some extent). Does anyone else have anything to contribute regarding TVCs vs. specific valve actives? Have I just been distracted by the things that a good active does well and missed a 'catch'. I don't have any nearby dealers / demo options so I'd probably go for a pre-built WD Pre3 based on what I heard last night but if there are better alternatives for similar money, I'd be interested to know about them.

Cheers

John
 
i've been in a similar dilemma for almost 2 years. i run a number of different TVCs, from S&B sourced via malaysian promethius to some very good local TVCs /better than stock models/ and i kept on coming back to EAR 864 which i believe shares some similar design principles with your active pre (for example, OPTs that is crucial for a quality of bass, drive and PRaT).
however it is my current situation of using an extraordinarily transparent and revealing speakers that also reproduce all the junk that comes via less-than-a-perfect active tube preamp. most of the listening time i clearly hear 864 distorting due to bad AC power (i have no filters and i hate most of them, i'm on a waiting list for a kemp power filter), tube quality or simply a comprimised design. i mean, you can listen to it, but there are moments where there's not much sense, so as soon as i drop a properly executed (C-core or double-C core TXs, a basic resonance control) TVC into a dynamic system capable of compensating a passives' general lack of drive, the difference in clarity is so bold though you obviously miss some of pulpability and a seductive way valve actives project the music into your room.
i believe the best answer would be to free an active pre from AC grid, however i haven't explored that field yet. another solution - a properly regulated PS-equipped monster that would make it pretty much independent from mains, but that's very very costly. the cheapest non-compromised pre made like this is around 4000E direct from a manufacturer, no middlemen
 
Last edited by a moderator:
anubisgrau said:
i've been in a similar dilemma for almost 2 years. i run a number of different TVCs, from S&B sourced via malaysian promethius to some very good local TVCs /better than stock models/ and i kept on coming back to EAR 864 which i believe shares some similar design principles with your active pre (for example, OPTs that is crucial for a quality of bass, drive and PRaT).
however it is my current situation of using an extraordinarily transparent and revealing speakers that also reproduce all the junk that comes via less-than-a-perfect active tube preamp. most of the listening time i clearly hear 864 distorting due to bad AC power (i have no filters and i hate most of them, i'm on a waiting list for a kemp power filter), tube quality or simply a comprimised design. i mean, you can listen to it, but there are moments where there's not much sense, so as soon as i drop a properly executed (C-core or double-C core TXs, a basic resonance control) TVC into a dynamic system capable of compensating a passives' general lack of drive, the difference in clarity is so bold though you obviously miss some of pulpability and a seductive way valve actives project the music into your room.
i believe the best answer would be to free an active pre from AC grid, however i haven't explored that field yet. another solution - a properly regulated PS-equipped monster that would make it pretty much independent from mains, but that's very very costly. the cheapest non-compromised pre made like this is around 4000E direct from a manufacturer, no middlemen
Click to expand...

I suspect that 'extraordinary transparency' is unlikely to be an issue for the forseeable future due to the non-ideal speaker/room interactions that I have to live with. Glass panelled internal doors, patio door, laminate floor etc. I'm also running Tannoy Lancasters so I'm not ideally on axis to the tweeters either. I'm really just looking for a sound I can enjoy until I can get a more ideal room and re-evaluate things. The TVC is fine in many respects (and I'll probably hang on to it anyway unless I really need the cash) but a bt more 'bounce' would be nice and the airy midrange of the Pre2 really made the Tannoys sing. What really amazed me about the Pre2 was how silent it was in operation and this had been my major concern in going active - I'd expected a bit of hiss but not a sausage.
 
you can always try to find a TVC based on more generous TX cores than what S&B uses in 102s (EI cores) - C or double C cores.

i believe that the music first statement or whatever that 8000 quid pre is called has one of these, but - unless you have some money for a quick laundry - you can check promitheus audio. i believe his recent TVCs are wound on C-cores.

my personal recommendations would be the TVCs made by solaja audio from belgrade but than i'm biased cause i heard them slaugthering any other TVC we put against them...
http://www.solajaaudio.com/index.php?page=preamps
(unfortunately it's only his valve designs mentioned on the link, TVCs are custom built. i've had his recent double C-core amorph TX pre over the weekend, i had to laugh how poor bent 102 based on S&B 102mk2 (OK, i know i know....) sounded against...)
 
Hi John

I would have a word with Glasshouse. Maybe there is a way of increasing the gain somewhat. Perhaps an alternation in the power amp or elsewhere may give you a few db more, and a bit more propulsiveness as a result.

I also agree with you that maybe this is just the difference between active and passive demonstrating the strengths of each type.
 
bottleneck said:
Hi John

I would have a word with Glasshouse. Maybe there is a way of increasing the gain somewhat. Perhaps an alternation in the power amp or elsewhere may give you a few db more, and a bit more propulsiveness as a result.

I also agree with you that maybe this is just the difference between active and passive demonstrating the strengths of each type.
Click to expand...

Just to be clear (if I understood you right): The TVC isn't 'underpowering' the power amp. I have enough dB for the whole neighbourhood (big Tannoys) and I rarely wind the volume pot past 10 o'clock. The improvement was one of scale and drive at the same (comfortable, ordinary) listening volume rather than the TVC running out of windings. Is that what you meant?
 
Hi - Yes, just wondering if the prefernce is a function of the extra gain on hand with an active pre.

Certainly I feel both designs have their advantages, the transformer passive it's neutrality, the active it's added energy.. as generalisations of course.
 
bottleneck has it spot on.I have the glasshouse tvc and compared it to a few of my active preamps.The tvc has too much gain for my system as my Cyrus power amps needs less than half volt for full power and the tvc with just 23 steps leaves me with little adjustment.The sound of the tvc is bare bones and swapping to active preamps puts the meat back on the bones.A drummer for instance goes from wearing trainers to wearing doc martins.Pays your money takes your choice i guess.
 
john dolan said:
bottleneck has it spot on.I have the glasshouse tvc and compared it to a few of my active preamps.The tvc has too much gain for my system as my Cyrus power amps needs less than half volt for full power and the tvc with just 23 steps leaves me with little adjustment.The sound of the tvc is bare bones and swapping to active preamps puts the meat back on the bones.A drummer for instance goes from wearing trainers to wearing doc martins.Pays your money takes your choice i guess.
Click to expand...

This more or less what I expected! Alas, CD needs some meat and Vinyl probably doesn't! I did like the big airy soundstage for Jazz and Folk though so I may give it a whirl anyway.

I'm suprised about your Cyrus comments though. I was a long term Cyrus user prior to my conversion to valves. I was using a Cyrus 8 integrated as a pre whilst awaiting delivery of the TVC and found I needed a few more notches on the pot when I switched over to the TVC.
 
I dont play loud though john the loudest i play is 70 db and that is very rare.I like to listen to up alnight on 5 live and on the lowest volume setting it was too loud.When i play cd it was too loud on no3 so i was always wanting a setting inbetween.I tried rothwell attenuators which helped but they were detrimental to the sound so Ive gone back to my Cyrus pre vs2 with psx because it gives me unlimited volume settings and its remote control and mc bus are things i dont want to lose.My brother dik built my tvc for me as a upgrade from the dale vishay passive and the volume settings with that were fine but the tvc just comes on too hot too soon.Mine was the first tvc kit they sold and the instructions were wrong and it had even more gain and dik sorted it out and told nick from hifi collective how to wire it correctly but even so the tvc on no2 is same volume as the dale vishay on about no6.Dik said if i wanted he could rewire mine for less gain but id lose the off possition.With a different power amp or less sensitive speakers the tvc would be a killer product.
 
Last edited by a moderator:
i have a feeling your problem lies elsewhere - too much gain in the system with speakers of high sensibility. get your power amp sorted, it's not a TVC issue
 
The problem with too much gain is only with my glasshouse tvc.With a dale vishey passive and another with a dact pot they are all fine and they all only have same amount of steps.No2 position on the tvc is like no 6 position with the others.
 
anubisgrau said:
i have a feeling your problem lies elsewhere - too much gain in the system with speakers of high sensibility. get your power amp sorted, it's not a TVC issue
Click to expand...

Previously, I had that very issue using 96dbl speakers, a MFA passive and a Canary 301mk2. The latter had an input sensitivity of .33 volts for full output, which meant I was confined to the first quarter on the MFA volume control. But it was dead silent ! Slightly less sensitive speakers would have put it in perfect electrically balance. But the pre and power are gone now.
 
guys, i know what are you talking about - i've had a 27db gain power amp into 115db eff speakers with a 3 V feed from a DAC via 0db TVC.

impossible to listen after 10pm even on the first click.

though the sound was great - a real headbangers ball!
 
IIRC it was Murray who thought that the first few notches sounded not so good through the S&B. Not sure if that was merely subjective or corresponded with the ringing that he recorded.
 
The ringing was much more pronounced the more attenuation was applied (ie the quieter you listened) It made using a power amp with high input sensitivity rather problematic.
 
murray - have you ever measured any other TVC or AVC? i remember graphs (was that you?) of S&B early ringing posted here. however a friend who's wounding his own TVCs - IMHO clearly better sounding that S&B 102 mk3 - measured his trannies and the ringing there occurs at much higher frequencies.
 
You could always add a resistive attenuator to the first volume notch, just for low level listening.
 
I looked at the Intact Audio Autoformers. They were far better than the S&B's both in terms of how they dealt with square waves and how they sounded.

I can quite easily believe that other TVC's could be wound which wouldn't ring at frequencies as low as the S&B's seemed to. I was quite surprised how poor the ones I tried were. Some later copper ones I subsequently borrowed didn't sound any better really although I didn't try firing any square waves through them, just music. I just presume its a sound some people like.
 

Latest posts

Back
Top