prometheus tvc matching

[himadri]

Hi guys
I am looking at the prometheus tvc as a preamp between the denon dcd700ae cdp - 2 volts /10 kohms and the power amp section of the denon pma2000ivr -0.9v/ 47k ohms. will there be enough gain? Any input will be highly appreciated
Regards and cheers
himadri

 

[jai1611]

What is the gain of your power amp section?

 

[himadri]

Jai
The gain (amplification factor) is 29 db.Also does the 10kohm impedance of the cd player seem right?
regards
cheers
himadri

 

[sidvee]

Hello
Gain is fine, see if you can locate the input sensitivity - lower the better - I used mine with the odyssey stratos extreme which had an an i/p sen. of 1v and it worked like a charm.
Cheers
Sid

 

[sidvee]

Here's a discussion on matching the tvc to amps. Hope it helps.

Odyssey Stratos Monos VS Parasound A21

Cheers
Sid

 

[jai1611]

10kohm is a bit high but manageable as long as your ICs are not inordinately long. I'm not 100% sure about the 29db power amp gain though. I think you will have to keep the volume know around 12 with that and a regular 2v source. That isnt a problem with the power amps I've tried it with.

 

[gobble]

Jai
The gain (amplification factor) is 29 db.Also does the 10kohm impedance of the cd player seem right?
regards
cheers
himadri

No can you check the specs again? A budget CDP may have output impedance in the range of 300-400ohms and the mid to high end one around 100+ ohms.

10K looks huge to me. The primary benefit of a passive pre should be in impedance matching, but your CDP specs dont look right.

--Gobble

 

[himadri]

Thanks jai,sid,and gobble
I have the denon dcd manual right in front of me and the specs read as:
output level 2.0v(10kohms) .So there it is gobble.
sid, as indicated in my post the input sensitivity of the power amp section of the denon pma2000ivr is 0.9v.That looks favourable.
jai,the source is 2v(the denon dcd700ae) but then then there is the issue of the high output impedance. (what exactly is a regular 2 v source)?
As for the rest of the chain, I am upgrading my present speakers ( definitive technology BP7004) with sensivity 92 db to the usher mini dancer1 with sensitivity of around 85db so i loose some gain there also.
What are your views guys?
cheers himadri

 

[sidvee]

Thanks jai,sid,and gobble
sid, as indicated in my post the input sensitivity of the power amp section of the denon pma2000ivr is 0.9v.That looks favourable.
As for the rest of the chain, I am upgrading my present speakers ( definitive technology BP7004) with sensivity 92 db to the usher mini dancer1 with sensitivity of around 85db so i loose some gain there also.
What are your views guys?
cheers himadri

Me thinks you should be fine with 0.9v i/p sens. and 29db of gain of the amp. Of -course you will loose a little bit of loudness due to the lower sensitivity of the Usher but it should not matter much. I was using the prom. tvc with odyssey stratos feeding the 718 which has roughly similar sensitivity and did not feel the need to turn up the tvc beyond 1 'o' clock. Of-course I listen to a lot of Jazz and not too much rock so that mattered.
Cheers
Sid

 

[odyssey]

Hi
The MD-1s are closer to 87dB (they are noticeably louder than the Be-718s) at the same volume setting. I seriously doubt the correct interpretation of the output impedance. Perhaps they are referring to 2V output when loaded into a 10Kohm input? I am not sure but the Denon site refers to this CDP as a low output impedance. NO ONE would call a 10k output impedance on an SS CDP as low.

cheers

 

[Asit]

Himadri,

As gobble has already suspected, and Sridhar has also questioned, it looks very unlikely for your Denon CDP to have such a high output impedance. It just could be that the CDP has 2 V output when connected with 10K Ohm input impedance. I suggest you write to Denon and be sure about it.

If it really turns out that the CDP has 10K Ohm output impedance (unlikely), given that input impedance of the amp is 47 K Ohm (by itself high), a passive pre would not work for you (as far as I understand), because the ratio is only 1:5 (while 1:20 is ideal and 1:10 is workable if the ICs are short and have low capacitance).

For explanations look for the first response in this discussion AudiogoN Forums: Question re matching pre and power amp impedance.. . Since we are considering a passive pre in your case, we can keep that out of the discussion for the moment and look at the output impedance of your CDP and the input impedance of the amp.

Regards.

 

[himadri]

Thanks Asit, Sridhar,Sid,
Well , the impedance issue seems to be a translation problem from japanese to english;
As per manual of the DCD700ae:Output level 2.0v(10kohms)
As per Brochure (from internet):Line out level (10kohms load) 2v
That clears the matter somewhat , as Gobble and Sridhar has guessed , the 2v rating is at 10kohm load.Does that satisfy the criteria?
Sid and Jai, The Audio Circle Prometheus forum contains numerous posts indicating poor response to quality/damage in transit issues and almost negligible after sales service from Nicholas especially since the beginning of 2010.What were your experiences?
Regards
Cheers
Himadri

 

[jai1611]

I havent had any issues. Communication from Nicholas was good - he answered my queries patiently. Shipping was prompt. The preamp was well packed. No trouble in operating it so never found a reason to check the after sales.

 

[sidvee]

Sid and Jai, The Audio Circle Prometheus forum contains numerous posts indicating poor response to quality/damage in transit issues and almost negligible after sales service from Nicholas especially since the beginning of 2010.What were your experiences?
Regards
Cheers
Himadri

Himadri - The first unit I ordered from Nicholas was damaged during shipment, but he asked me to send it back and he sent me a brand new unit which worked flawlessly. This was 2 years ago so am not sure how his service is now.
cheers
Sid

 

[Asit]

As per Brochure (from internet):Line out level (10kohms load) 2v

That seems like what Sridhar was suggesting: 2V output when connected to a 10K Ohm load. In any case, it is better to ask Denon for a number on the output impedance of the CDP to be absolutely safe.

There was a point (before I finally bought my tube integrated) when I was considering the Stratos amp with a passive pre. I considered the Promitheus TVC very seriously. Nicholas seems to be a very busy guy, but he always answers within 24 hours, at least it was to me. He also offered me a good discounted price on top of shipping costs completely waived (there was a deal going on at that time). Any way, I finally did not get the TVC, so cannot tell you any more.

Regards.

 

[himadri]

Thanks Asit,Sid,Jai for your prompt replies.
Asit, yes i shall check with denon on that issue .Of course I have gone through that great thread and know how you made your final choice.I shall have my mini dancer 1s by this month end and maybe decide on the pre after the audition.Generally as per the user experiences on the net, the denon PMA2000ivr sounded better with a passive pre or a tube pre.But as my budget is already exhausted on the mini dancer , I was looking at a cost effective amplifier upgrade.
Sid and jai ,thanks for sharing , I shall take the final call after installing the ushers.
regards
cheers
himadri

 

[sidvee]

Good luck Himadri - Just my experience with the promitheus - an excellent value and superb sound - IMHO the best value in high end audio today - I regret selling it but wasn't using it enough to justify it.
Cheers
Sid

 

[himadri]

Thanks Sid
Shall keep you all posted about the developments after the ushers are installed
cheers
himadri

 

[hifiashok]

where r u based out of pl.? there's someone in g'gn who i kno has two prom tvc based prez, one of which is a much modded apollo!! have been trying but does not seem to have my moniker on it.

 

[himadri]

hi ashok
Im based out of Bhilai, Chattisgarh.Couldn,t Get the other part of your query.
regards
himadri