Promitheus TVC passive preamp anyone?

GHM · « **on:** 20 Sep 2006, 05:28 pm »

Just wondering if anyone else here has received their unit. Mine just showed itself today. The wait has been pretty aggravating I must admit. Not the shipping part, just the wait on the build. DHL is extremely fast I must give them a

for the fast deliver. The unit shipped out of Malaysia on Monday..it was at my door step before 10:30 a.m this morning..two days around the world.

Still listening gathering my listening impressions. I will say I didn't expect the build quality of this unit to be what it is. It is one beautifully made little preamp and heavy for its size. I know Nicholas of Promitheus has had some shipping issues and QC problems in the past. Just hickups of a small company normally starting out..no biggie. I don't see or hear any of that in this unit so far.

More later

Bwanagreg · « **Reply #1 on:** 20 Sep 2006, 06:32 pm »

I came home early today but missed my DHL driver by an hour. DHL destroyed my first unit, so I'm still crossing fingers. Glad yours arrived safely!

GHM · « **Reply #2 on:** 20 Sep 2006, 07:01 pm »

Hi Greg..you maybe able to go by the DHL terminal and pick your unit up. That's if you know where it is located. Some of the drivers in my area are normally back at the terminal by 6 p.m. if not before. I would think the same in your area.

Bwanagreg · « **Reply #3 on:** 20 Sep 2006, 07:11 pm »

Yup, that's the plan. He'll be back by 4:00. I don't usually go home early for a delivery but I have skin in the game now and I want my TVC!

GHM · « **Reply #4 on:** 20 Sep 2006, 10:04 pm »

Greg..it will be worth it!! I've been listening to this thing for over 5 hours now. Pretty much non-stop.This is my first foray into TVCs and from the sound of this one ...probably my last.

Compared to my noble pot . The Promitheus has more depth and width. I like how it does the music at very low volumes. Even at whisper quiet levels I still get everything from top to bottom in sound. The transients don't get squished at all!! It has the bass and transient attack of a good active preamp without additional noise.

This isn't a thin, brittle sounding preamp unless the front end is already brittle from the start I imagine. From talking to one owner..he described the preamp as having tone. I couldn't agree more..it does have a great tonality. The great thing is that it does it without loss of detail or transparency. It doesn't sound forward or harsh in anyway. I was a little nervous about trying this with my Chip amp...no worries though. I could almost be fooled into thinking there are tubes hidden some where.

Now I understand why Nicholas offers a 30 day money back guarantee. Most wouldn't want to send this unit back. This one is here to stay.

I communicated with one person who tried it. He got bleeding highs and no bass. Not sure what the problem was? He used very expensive equipment Wadia and Wolcott monos. So it seems regardless of how expensive the gear is.You still have to be careful how you match up the TVC to the source and amplifier.

Anyone using a Noble volume pot in their preamp or integrated needs to hear what they've been missing. I've tried amplifier direct with CDP and active preamps. As well as resistive type passives like the Noble pot and shunt type resistor controls. The TVC has been the best fit for me so far.

Cheers

nzera · « **Reply #5 on:** 20 Sep 2006, 10:23 pm »

What's the wait on these?

GHM · « **Reply #6 on:** 20 Sep 2006, 10:28 pm »

Quote from: nzera on 20 Sep 2006, 10:23 pm

What's the wait on these?

Hello, I waited roughly 4 weeks for mine. I believe Greg's may have been closer to 5 weeks.

Cheers

Bwanagreg · « **Reply #7 on:** 20 Sep 2006, 11:00 pm »

It was just shy of 6 weeks.

So I picked it up a couple of hours ago (you can tell where this is going I bet). No shipping damage (although I had a scare when I saw a small hole poked into the box - no harm done).

But.

The volume knob has a defect (one channel drops out at the tenth detent). Sigh.

Also, there is hum. I hate hum.

Gymane, do you have any hum coming from the unit? I'm getting noticeable levels on one channel (the same with the volume defect - coincidence?) on the inputs that are unused , or when I crank the volume with the DAC off. It is worse when the DAC is on. I emailed Nick a minute ago to see if this is a defect as well or if these things are susceptible to hum. I have a tube amp right above it and a bunch of wireless devices in the house. None of the rest of the audio equipment in the house has any hum at all though, including the Adcom 565 I hope (had hoped?) to replace with the TVC in the same system. This is a deal breaker for me unless it's a defect.

By the way, I agree with your assessment of the sound so far. I would describe the sound a rich and detailed. It opened up a lot in the first hour, and I understand these things have a long break in period. That's the only reason I haven't thrown in the towel already. This is unit #2 for me, but the first was DHL's fault. And it is really cheap.

GHM · « **Reply #8 on:** 20 Sep 2006, 11:47 pm »

Quote from: Bwanagreg on 20 Sep 2006, 11:00 pm

It was just shy of 6 weeks.

So I picked it up a couple of hours ago (you can tell where this is going I bet). No shipping damage (although I had a scare when I saw a small hole poked into the box - no harm done).

But.

The volume knob has a defect (one channel drops out at the tenth detent). Sigh.

Also, there is hum. I hate hum.

Gymane, do you have any hum coming from the unit? I'm getting noticeable levels on one channel (the same with the volume defect - coincidence?) on the inputs that are unused , or when I crank the volume with the DAC off. It is worse when the DAC is on. I emailed Nick a minute ago to see if this is a defect as well or if these things are susceptible to hum. I have a tube amp right above it and a bunch of wireless devices in the house. None of the rest of the audio equipment in the house has any hum at all though, including the Adcom 565 I hope (had hoped?) to replace with the TVC in the same system. This is a deal breaker for me unless it's a defect.

By the way, I agree with your assessment of the sound so far. I would describe the sound a rich and detailed. It opened up a lot in the first hour, and I understand these things have a long break in period. That's the only reason I haven't thrown in the towel already. This is unit #2 for me, but the first was DHL's fault. And it is really cheap.

Hey Greg when I first plugged the unit up I got a slight hum. After my buffer powered down and I restarted it. The hum was gone. I have to be standing next to the speaker with my ear several inches away from the driver and the volume opened up more than half way to hear any noticeable noise or hum. I have my Monarchy Upsampler sitting on top of the unit.

I hate to hear that. I owned a SE Adcom 585. I tried to use it with a passive a few years back.It had a really bad hum.So bad I couldn't listen too it. I'm not sure but it sounds like you have a ground loop and the amplifier is causing the problem.

I've read the unit needs 100 hours or so to open up completely. The kicker is you need to do this at each setting unless you use resistors to burn it in with the volume knob full blast. No amplifer hooked to it of course.

What's the output impedance of your Dac?

Bwanagreg · « **Reply #9 on:** 21 Sep 2006, 12:14 am »

The soundstaging is really amazing. My wife picked up on the improvement imemdiately without prompting - it sound more "present" in her terms. I'm amazed at how warm (in a positive sense) the sound is.

The tenth detent problem is unacceptable, so I'm not going to agonize over the hum problem yet. It is only an issue when there is no signal present (unused inputs, etc.) and I need to either get a replacement or a refund. So much promise, so many problems. I'm going to sleep on it.

GHM · « **Reply #10 on:** 21 Sep 2006, 12:24 am »

Yes I noticed this also pretty much off the bat with the openess. It does get better as juice flows threw it.

I'm thinking it's something else causing the problem. What's the output impedance of your DAC? Another device maybe trying to use the preamp as a ground. Do you have another amplifier or source you could try with the unit?

Bwanagreg · « **Reply #11 on:** 21 Sep 2006, 12:52 am »

Yes to both. I have a battery powered Tripath amp built by Wayne, and a RAM CD deck. I still have my old Adcom DAC also, plus a couple of OneACs I can try to see if power supply isolation helps.

It seems strange that the hum is only a problem with the TVC though. The Adcom in the same system has zero hum of any kind.

I'll try swapping components over the weekend - I blew off enough work today to get this far ...

GHM · « **Reply #12 on:** 21 Sep 2006, 01:00 am »

Quote from: Bwanagreg on 21 Sep 2006, 12:52 am

Yes to both. I have a battery powered Tripath amp built by Wayne, and a RAM CD deck. It seems strange that the hum is only a problem with the TVC though. The Adcom in the same system has zero hum of any kind. I'll try swapping components over the weekend - I blew off enough work today to get this far ...

Yup I know..I couldn't understand it either. The Dared preamp I used at the time I had the passive and the 585 presented no real hum. As soon as I put the Passive in the loop it showed its ugly head. This is where I concluded it was a grounding or impedance issue or maybe both.

I hear ya on blowing the time. Glad I was off work today..lot of play around time

.

NewBuyer · « **Reply #13 on:** 21 Sep 2006, 02:36 am »

I have a Promitheus Audio TVC also, and find it to be an excellent preamp, in fact truly superb.

About the hum: I think the transformers in the TVC are VERY sensitive to proximity to other powered components, and especially sensitive to their power cords. Are you putting the DAC on top of the TVC? If so, try moving the DAC to a position farther removed from the TVC, especially making sure the power cords of all other components are well removed from the TVC and all its RCA inputs. When you switch to an unused input on the TVC, you may hear interference hum, as the unused RCA inputs pick up ambient electrical noise from the proximate area and pass it right into those internal transformers. As soon as you "use" the input (by attaching a component to it with RCA cables), the hum disappears - again assuming you have the TVC well-removed from other components (especially those power cords around the TVC inputs). Best of all I believe is when the TVC is on the top shelf of your system, well above all other units, and nowhere near any power cords.

You might try Cardas RCA Caps on your unused RCA inputs, it might make a big difference as well in this situation.

Bwanagreg · « **Reply #14 on:** 21 Sep 2006, 02:33 pm »

Nicholas replied to me last night (we have a 13 hour time difference to cope with) and he stated that a broken wire (which I obviously have) can cause hum. I did try moving the DAC, amp and preamp away from each other more and it did not make a difference. I think a ground loop is a possibility, but I won't get a chance to try many more things until the weekend. I'm placing odds on the broken wire theory at this point, but who knows.

Apparently Nicholas is looking to redesign the case a bit (using a new metal plate) to make it sturdier in shipping. DHL seems to have it out for me. I failed to mention (becasuse I thought it wasn't relevant at first) that the shipping box was punctured. It didn't case any damage to the TVS's case, but it might indicate rough handling that is causing the problems.

I appreciate all of the advice. I listened to some of my favorite reference tracks last night and continued to be impressed by the sound of this thing, and it's barely broken in -- just broken

Nicholas is being responsive about all of this. Apparently seven units have shipped to the US with no problems. I just drew the short straw.

GHM · « **Reply #15 on:** 21 Sep 2006, 03:04 pm »

It sure seems that way my friend. I've been listening to this unit through the morning. I just can't get enough of the music it puts out!! Recordings that I once had a hard time listening too are now very listenable. I'm going out this morning and buy some more Cd's! I'm salivating to hear some new stuff with it

. I finally found the last piece of the puzzle for my system. I was starting to wonder if I could get musical and transparency in the same package without brightness or vagueness.

I look forward Greg to reading more of your impressions about this unit. Hopefully the next one will arrive without incident.. three's a charm.

I think Nicholas also has a TVC phono stage in the works. Maybe when I get the nerve and money to try vinyl. He'll have it perfected. I'm without a doubt hooked on his offerings now. I haven't visited 6moons lately but noticed last night that a review is scheduled for the TVC-1 and my Burson buffer..can't wait to read them.

Thanks for chiming in New buyer...great to see others taking the dip and enjoying it.

lonewolfny42 · « **Reply #16 on:** 22 Sep 2006, 07:36 am »

Gymane....You didn't post a link for the Promitheus TVC...so here's the site......

Sounds like your enjoying it...it looks good.

Wonder how it compares to my Bent NOH ? Have you tried a Bent ?
Chris

JLM · « **Reply #17 on:** 22 Sep 2006, 09:22 am »

Gymane,

What happened to the Single Power tube pre-amp? Please compare.

Just as I was striving to add tubes to my similar system (same speakers, Channel Islands Audio chip monoblock amps, and newly acquired Ah! Njoe Tjoeb 4000 with all the options), you've pulled the rug out from under me!

Thanks for advice on another killer product (and Chris for the link).

I noticed that they also offer to package 1 meter silver interconnects for just $50 extra.

samplesj · « **Reply #18 on:** 22 Sep 2006, 01:57 pm »

Ok, I've got to take a frustration break from work so I'll reply here as a cool down.

It looks like the transformers this TVC uses are unshielded. It also appears that it is a wood case vs metal for shielding. That may explain why it is sensitive to external EMI/RFI. The S&B units are encased in a mu metal shield to help block interference and leakage. I actually have my TVC units in the same metal case as a pair of UCD400 modules, power supply, and 1000va transformer with no hum (on the other side as far away as possible of course).

Because a TVC isn't traditionally connected to power it doesn't have an external ground source to cause a differential ground hum on its own. A wiring mishap could easily cause issues and as pointed out EMI/RFI might, but overall it shouldn't hum at all.

Regardless of who makes the transformers its still a TVC so welcome to the club. I agree they are something special. Enjoy!

GHM · « **Reply #19 on:** 22 Sep 2006, 02:54 pm »

Thanks Chris for the link my friend. I told a buddy here in town about your Dac. He wants one so bad now after my description he's almost miserable.

.

I haven't heard the Bent unit. So I can't say one way or the other. What I do know is I haven't heard ANYTHING like this in my audiophile career.

JLM...I sold the Single power unit. My Single power unit used a pot plus at the time my integrated wasn't fit to run direct. So I cured the problem by having it made to run direct. I've been wanting to try the TVC for a long time now. Finally one not too expensive shows itself. I also wanted to lower the gain which my Single power had plenty of... almost too much for the Gain clone.

It's a tough comparo between the two. Being the TVC has no gain and no noise what so ever. The transparency thing it does without sin. The Single power unit has tremendous dynamics and bass. The TVC is more polite in these areas..not polite in a bad way just more subdued. It is as dynamic or more dynamic as some actives I've spent time with. For example the EE minimax cannot match this unit on any front IMHO. It lets the music's flow and temper be heard all the time. No truncated lows or highs..above all else it is musical and totally nonfatiguing. To be honest I didn't know SS gear could sound like this only tubes...I was wrong.

The biggest thing about the TVC is how you can listen to music. No matter the volume. Even at the lowest setting..you get delineation and contrast..along with bass definition. This is something I haven't heard from any preamp that uses a resistive volume control.

As mentioned before this isn't a thin sounding unit. It sounds warmish in a good way. For the lack of a better word..its got TONE and a ton of it! I listened to some Kelly Joe Phelps(Tunesmith Retrofit) last night. On the the anvil track my seat vibrates from the bass notes. This is with the volume set at 9 o'clock and the listening level around 60 dbs. It was nearly 2 a.m. this morning. I use silver /copper ICs from the Promitheus to the amplifier. Basically everything else is Blue Jeans..which I will eventually replace the one pair of ICs with.

Thanks for your input samplesj. From what Nicholas said... a broken wire could be the problem. I use my unit in the cabinet with 5 other devices all powered and it's also near the TV. There's no noise from this TVC. This is with a powered device sitting on top of it directly. The Volex powercords must be doing their job. This is a very simple unit no frills..but Oboy it's a beautiful little unit. For the price of admission..I personally don't know of a preamp that can match it on all fronts musically. You'll have to spend a lot too embarrase it..I mean thousands not hundreds. It won't be long ..I gather the price will go up. It is almost silly what this unit can do, and to think I almost canceled the order.Thanks for welcoming us to the club..I'm here to stay.