Promitheus TVC passive preamp anyone?

brashgordon · « **Reply #480 on:** 6 Dec 2006, 07:30 am »

Nicholas promised mine would be shipped Monday 12-04 ....

Mein Gott .... I hope this happens ....

I've been reading this thread since the first of October ...
when I placed my order ... and then started adding upgrades ...
without entirely knowing why ... LOL

just keep getting this "warm" feeling .... deep down in my guttiwuts ....
searching for the sound of "angel trumpets and devil trombones" ....

the old Ludwig Van ....
peeled orange timepieces ... on the Moloko plus...

Now on to the Paradisea pipeline .... and the tube variants ... geeze

I hope I don't do anything .... REAL horrorshow .......

Like buy solid state .... or a Bose table top ..... LOL

There's NOT a Bose thread here .... is there ????

lonewolfny42 · « **Reply #481 on:** 6 Dec 2006, 07:40 am »

Quote from: brashgordon on 6 Dec 2006, 07:30 am

There's NOT a Bose thread here .... is there ????

Catch a Wave.....and you'll be sitting on top of the world.....

Beach Boys......

JLM · « **Reply #482 on:** 6 Dec 2006, 10:48 am »

Jim,

I had a modded SB3 with VMB-1 driving less efficient speakers (88 dB/w/m) and it was barely an issue nearfield in an 8 ft x 13 ft x 21 ft room. Now with a higher voltage source its not an issue.

Not sure if the driver change you suggest will provide much more than a marginal improvement (2 wpc just ain't much). I tried a modded Clari-T for a few months with these same speakers and while it worked remarkably well, I knew it wasn't fully synergistic. My advice is to size the amp to provide a commanding grip of the speakers. Nummerically that means that the pairing should at least be able to reach 105 dB in your room (110 dB would be better), at your listening position:

small room, nearfield, two channels = 4 dB
Abbeys = 95 dB
therefore the amp should do at least 6 dB (5 wpc) of gain, 11 dB (13 wpc) would be better.

You're at least "in the neighborhood" and as a second system I wouldn't lose much sleep over it, but YMMV.

jrebman · « **Reply #483 on:** 6 Dec 2006, 01:00 pm »

Quote from: JLM on 6 Dec 2006, 10:48 am

My advice is to size the amp to provide a commanding grip of the speakers. Nummerically that means that the pairing should at least be able to reach 105 dB in your room (110 dB would be better), at your listening position:

small room, nearfield, two channels = 4 dB
Abbeys = 95 dB
therefore the amp should do at least 6 dB (5 wpc) of gain, 11 dB (13 wpc) would be better.

You're at least "in the neighborhood" and as a second system I wouldn't lose much sleep over it, but YMMV.

JLM,

Not sure I agree with your calculations. For every 3dB increase you double the power, therefore 1w=95dB 2 watts = 98 db, which is more than enough for this situation A 110dB peak in this room would kill me. Terry Cain used another, lower power variant of this 6EM7 amp for this speaker and I'm sure he liked it as he ended up buying 6 of them.

But this isn't the point of my original request, so maybe if you could take your TVC and connect the output of your modded SB to it and then about 10 - 12 feet of interconnect between it and the input of your amp, then tell me how it works, that would be great. It's all a question of whether or not the 1.1 vrms out of the modded SB will sufficiently drive 12 feet of IC into an amp with a sensitivity of 1vrms for full output into a 150k load. I'm sure it will work no problem from the output of a Paradisea but directly from the SB seems borderline.

-- Jim

rollo · « **Reply #484 on:** 6 Dec 2006, 04:34 pm »

Hi GHM, Yes I run the 924 model 22 tweeters and 9 mid's per side 6'-6" tall.No crossover to the subs I run them off the Cyber 211's with AntiCable.Sub set at 55hz.There set 1/3 of the room length out from the rear wall[6'] 7' apart.Listening position is 10'. These replaced my Maggie 3A's driven by Audio Research 250mk2 servo[250 watt triode]. Rollo

jaspal kallar · « **Reply #485 on:** 7 Dec 2006, 12:45 am »

Hi,

I wonder if anybody had tried the Promitheus TVC passive preamp with Promitheus's own silver cable which sell for around $55 (RCA) ?

The reason I ask is that it looks like, according to Nicholas, that my single ended in (from my dac) will not translate to XLR balanced out to the power amp. My last preamp allowed this and of course it was doing some kind rca to xlr balanced conversion before it sent it to my power amp. So now I have go single ended to single ended. Hence my question about Promitheus's own silver cable.

I'm ready to order, just waiting for Nicholas to confirm that my system specs are okay with the Promitheus TVC.

- jaspal.

JLM · « **Reply #486 on:** 7 Dec 2006, 11:04 am »

jaspal,

No longer have the SB3 and am waiting for the dust to settle on Promitheus design tweaks before ordering.

You're right, a continous 110 dB is extremely loud, but the amp/speaker must be able to handle the peaks. In my case 8 wpc made the 88 dB/w/m speakers into very pleasant gentlemen, but 30 or 40 wpc turned them into NFL linebackers in tuxedos! (more impact, control, and finesse)

My numbers for the room and nearfield setting are "pulled out of the air", but are close. In a 2,000 cu ft room there is about a 3 dB drop from the 1 meter free air rating measurement, but adding a second channel adds 3 dB back. Sitting nearfield (which for me is less than 6 feet) adds 1 - 2 dB. So to reach 105 dB with a pair of Abbys in a small room (nearfield conditions being pretty much a given in a small room to start with) you need 105 - 95 -4 = 6 dB of gain, which is just under 5 wpc.

gooberdude · « **Reply #487 on:** 7 Dec 2006, 03:03 pm »

hey Jaspal,

I have a pair of nick's silver IC's, i think they sound nice but took quite a while to break in. These are the 1st silver IC's i've tried. also, they don't work well between the TVC and my amp. Similar to another set of unshielded IC's i own, a hum is audible. However, i really like the silver IC between source & TVC. nick has a new design too i think.

jaspal kallar · « **Reply #488 on:** 7 Dec 2006, 03:26 pm »

Quote from: gooberdude on 7 Dec 2006, 03:03 pm

hey Jaspal,

I have a pair of nick's silver IC's, i think they sound nice but took quite a while to break in. These are the 1st silver IC's i've tried. also, they don't work well between the TVC and my amp. Similar to another set of unshielded IC's i own, a hum is audible. However, i really like the silver IC between source & TVC. nick has a new design too i think.

gooberdude:

Thanks for your reply. It was infact between the TVC and amp I was thinking of using them. Maybe I'll just get a shielded version RCA of my current XLR branded cable. I presume then you do infact have a shielded cable between the TVC and amp?

Has anybody else had a hum problem when using a unshielded cable between the TVC and their amp?

- jaspal

GHM · « **Reply #489 on:** 7 Dec 2006, 07:30 pm »

Quote from: jaspal kallar on 7 Dec 2006, 03:26 pm

Has anybody else had a hum problem when using a unshielded cable between the TVC and their amp?

- jaspal

I use unshielded cables between the the TVC and the amplifier...no hum problems at all.

Randy · « **Reply #490 on:** 7 Dec 2006, 07:38 pm »

Has anybody else had a hum problem when using a unshielded cable between the TVC and their amp?

- jaspal
[/quote]

I use unshielded cables between the the TVC and the amplifier...no hum problems at all.
[/quote]

Same here. I use an XLR three strand silver cable in an unshielded teflon tube between the TVC and my amps and have no hum, in fact between the notes there is utter silence .

gooberdude · « **Reply #491 on:** 7 Dec 2006, 07:49 pm »

I get the hum with both a Mapleshade Clearview IC and nick's silver IC...it could easily be an issue with my amp though. the hum was evident with previous preamps and the mapleshade cable.

a few weeks back i tested nick's cable inbetween pre/amp, and for a few minutes there was no hum and it sounded great...then all the sudden it came back.

inserting the anti-IC's back in place solved the issue 100%...probably a system dependent issue.

i do think nick's cable is well made and sounds great though.

cutcopypaste · « **Reply #492 on:** 7 Dec 2006, 11:15 pm »

Hey guys I have had three TVC for about three weeks. Very good pre-amp, very revealing. I have now started looking for a new cd player to compliment it. I'm testing a Shaling CD100 at the moment. One question about volume position, the TVC with Shaling doesn't get really interesting, until the 10-11 o'clock postion. Is this normal? The DAC I use gets interesting at about 7-8 o'clock postion. I know this is probably an output voltage issue, but I thought I would get your feedback.

GHM · « **Reply #493 on:** 7 Dec 2006, 11:29 pm »

Quote from: cutcopypaste on 7 Dec 2006, 11:15 pm

Hey guys I have had three TVC for about three weeks. Very good pre-amp, very revealing. I have now started looking for a new cd player to compliment it. I'm testing a Shaling CD100 at the moment. One question about volume position, the TVC with Shaling doesn't get really interesting, until the 10-11 o'clock postion. Is this normal? The DAC I use gets interesting at about 7-8 o'clock postion. I know this is probably an output voltage issue, but I thought I would get your feedback.

That's exactly what it is..your Dac must have a higher voltage output.

jaspal kallar · « **Reply #494 on:** 8 Dec 2006, 12:35 am »

Quote from: gooberdude on 7 Dec 2006, 07:49 pm

I get the hum with both a Mapleshade Clearview IC and nick's silver IC...it could easily be an issue with my amp though. the hum was evident with previous preamps and the mapleshade cable.

a few weeks back i tested nick's cable inbetween pre/amp, and for a few minutes there was no hum and it sounded great...then all the sudden it came back.

inserting the anti-IC's back in place solved the issue 100%...probably a system dependent issue.

i do think nick's cable is well made and sounds great though.

gooberdude:

I've never so far had any need for shielded IC's, so hopefully won't in the future. As you say you had hum before in previous pre/amp. So yes probably a thing with your system.

Randy, GHM:

Thanks for the replies. I think I will order the silver IC's as well. I just looked at the price and 55 USD + effective free shipping it's seems a good deal. Here in Sweden even a very average IC costs around 55 USD. I get the impression that Nick's Silver cable would be much better.

I have general question for you USA folks. When you buy from overseas, say for example the TVC what are you import taxes?

For me, here in Sweden it's = [ 3.5% x (cost of article + shipping cost) ] x 25%. So basically for importing one has to add on around 30% as a rough figure. I was just curious to what the costs were like in the US, hence my question.

Thanks,

- jaspal.

cutcopypaste · « **Reply #495 on:** 8 Dec 2006, 01:40 am »

[/quote]

That's exactly what it is..your Dac must have a higher voltage output.
[/quote]

Sorry if this sounds nurotic but at what volume position does your TVC hit its sweet spot?

rollo · « **Reply #496 on:** 8 Dec 2006, 01:54 am »

jaspsl, no taxes that i'm aware of.We probably have a trade aggreement with Malaysia..
rollo

GHM · « **Reply #497 on:** 8 Dec 2006, 02:14 am »

Quote from: cutcopypaste on 8 Dec 2006, 01:40 am

Sorry if this sounds neurotic but at what volume position does your TVC hit its sweet spot?

With the Paradisea..my volume sweet spot is 9 o'clock. With my Audio Sector Dac it's 10 or 11 o'clock. The voltage output of the source and the sensitivity of the amplifier will cause this the vary from setup to setup.

NewBuyer · « **Reply #498 on:** 8 Dec 2006, 02:47 am »

Of course, time-of-day makes a big difference to the volume position too.

For late night listening at lower volumes, I've never found any other preamp as satisfying as the TVC. For higher volume listening during the day/weekends, it is just as interesting/involving too.

I really find no faults from the TVC at any of the volume levels, and interestingly, I find this to remain true when using the TVC with a nice variety of different audio equipment configurations.

jaspal kallar · « **Reply #499 on:** 8 Dec 2006, 06:27 pm »

Quote from: rollo on 8 Dec 2006, 01:54 am

jaspsl, no taxes that i'm aware of.We probably have a trade aggreement with Malaysia..
rollo

What are the taxes say if you are importing from Europe, say the UK?

Btw, I ordered yesterday, the balanced version plus the RCA Silver IC. Nicholas thought it would take approx 3 weeks to build. I've gone for the slower Registered Air Shipping to here in Sweden since the budget was tight (orginally only wanted to pay as much as for the Axiom). So in all in with xmas/new year and slower shipping I'm hopefull or having in my possesion within say max 2 months. Can't wait

- jaspal.