Nagra HD Preamp Versus Aries Cerat Incito S Preamp

[Salectric]

From the Nagra literature, it appears the HD uses a single active stage which is a 6dj8 with the plates in parallel, configured as a cathode follower. A cathode follower has zero gain but it has a very low output impedance. This single active stage is really just a buffer that feeds a transformer volume control which lowers the output impedance even more. A transformer can be configured to provide some gain although you then lose the benefit of the lowered output impedance.

 

[Salectric]

Nagra describes the HD circuit rather misleadingly as two stages—-a current stage (the zero-gain 6dj8 cathode follower) and a voltage stage (the transformer volume control). In reality it’s a single stage preamp with an attenuator on the output.

 

[jfrech]

Hi Ron, one more point that the mono and stereo article makes that I forgot. Because of the unique volume control, it's not attenuating the signal then re-amplifying it. Therefore maybe less is more....

 

[Ron Resnick]

Thank you for weighing in!

Hi Ron did those two 8 db gain preamps have multiple output voltage settings?

No; neither of those preamps had an adjustable gain option. The VTL does, and with the Jadis amps I used it on the high gain setting.

In the case of the Nagra HD I don't think your conclusion on gain (alone) is the whole story to mate properly with your amps...

I just know that in my system with my phone stage and my cartridge in my amplifiers and in my room and at my listening levels 5.6dB ain't enough gain.

Nagra's marketing info is pretty bullish "...output impedance is as low as 0.2 Ohm so that you can drive any amplifier on the market."

Yes, output impedance is an important consideration for amplifier matching and for interconnect matching, but this has nothing to do with native preamp gain.

Final point, I am pretty sure the output transformers deliver another +6db of gain....which is why I am at the 1v setting ....

My system is entirely single-ended.

 

[microstrip]

Really? You're going to attempt a forensic analysis of my usage of my own system in my own home at my own preferred listening levels to try to prove I did something wrong?

No, just to understand your typical naive questions and give my opinion in such affairs. This subject is really an important question - surely sometimes my positions question usual dogmas and I am happy to debate why.
And individual subjective experience sometimes surpasses our preferred criteria - we must be able to accept it, and if possible understand why.

With both Hegel P30A and Incito S (8dB gain version) the volume control is at maximum (minimum attenuation) at normal or below normal listening level.

Probably your speaker system is insensitive or the amplifier has low gain. The VTL 7.5 mk3 will be hard to beat in such case. In case you give me the typical volume level you used in the 7.5 I will able to tell you the gain you were using I calibrated it in order to carry fair comparisons with other preamplfiers. Lamm preamplfiers would be excellent in this aspect for you - the usual complain is that they have too high gain.

 

[microstrip]

Is it possible that the professor is not correct?

The HD PREAMP HV offers a solution to this problem by providing a variable input level on one RCA and two XLR inputs. A toggle switch next to the left input of RCA3 does not provide any gain (low) or adds 12dB gain (high) to RCA3 on both channels. And a toggle switch next to each left XLR input sets no gain (low), 12dB gain (high), or 10V input voltage capacity (studio level) for each XLR of both channels.

NAGRA HD PREAMP HV REVIEW – M & S | Ultimate High-Fidelity

www.monoandstereo.com

Thanks to 213Cobra for this information.

I asked you if you were getting a Nagra HD or a Nagra HD HV. You said an HD. So, I quoted Paul Miller HifiNews review of the HD, did not look for the HV.

Some time ago I considered an used Nagra complete HD preamplfier, HD amplifier and DAC system that our D'Agostino dealer accepted in part exchange for a D'Agostino system. The Nagra's were like new, the price was very nice, I discarded it because I had been told it was an HV and when I looked inside it was not. The friendly advice of our member jfrech was very useful in such decision because I asked the proper question...

BTW, fortunately for both of us I am not your professor ...

 

[Argonaut]

Jeeezuzzz … How difficult is it to comprehend ?!?! … For the most part designer’s of audio equipment factor in a fundamental circuit and component synergy between the units that they end up putting into production … Sometimes those design parameters such as gain , connectivity , etcetera are symbiotic between their component parts … Ergo If you want a Nagra Pre Amplifier pair it with a synergistically matched Nagra Amplifier , Same goes for Atma-Sphere , Robert Koda , Aries Cerat , Kondo, NAT….Ad Infinitum !

 

[LL21]

I'd sure like to know of anyone's experience with the Nagra Reference DAC- a tube DAC that I'd love to know more about. I think its so new that it isn't even on the Nagra web site yet.

View attachment 144867

Agree!

 

[microstrip]

Jeeezuzzz … How difficult is it to comprehend ?!?! … For the most part designer’s of audio equipment factor in a fundamental circuit and component synergy between the units that they end up putting into production … Sometimes those design parameters such as gain , connectivity , etcetera are symbiotic between their component parts … Ergo If you want a bloody Nagra Pre Amplifier pair it with a synergistically matched Nagra Amplifier , Same goes for Atma-Sphere , Robert Koda , Aries Cerat , Kondo … NAT ….Friggin infernitum !

Although I agree with you, for some time I used the Audio Research REF40 with the VTL Siegfried II, although I owned the VTL 7.5 mk3 preamplifier. There was something very special in the way the ARC preamplfier filled the big soundstage with life and dynamics that was hard to resist, although the VTL was far more more neutral. Before you ask, I tried the ARC Ref750 but was put away by the heat and the very high and frequent tube replacement cost. But after a long listening and mediation you win - I am selling all the amplification gear, keeping a conrad johnson GAT2 and the ART monoblock amplifiers, also for their unbelievable synergy . Wisdom is slowly winning, but sometimes with some sadness ... Decent offers for the VTLs are welcome to overcome it!

 

[Argonaut]

Although I agree with you, for some time I used the Audio Research REF40 with the VTL Siegfried II, although I owned the VTL 7.5 mk3 preamplifier. There was something very special in the way the ARC preamplfier filled the big soundstage with life and dynamics that was hard to resist, although the VTL was far more more neutral. Before you ask, I tried the ARC Ref750 but was put away by the heat and the very high and frequent tube replacement cost. But after a long listening and mediation you win - I am selling all the amplification gear, keeping a conrad johnson GAT2 and the ART monoblock amplifiers, also for their unbelievable synergy . Wisdom is slowly winning, but sometimes with some sadness ... Decent offers for the VTLs are welcome to overcome it!

Oh For Sure , there will oft times exist a pleasing synergy between carefully chosen components from disparate manufacturers .. … however that usually entails a fair degree of research , due diligence and often no little trial and error on behalf of the intrepid audiophile. In essence my point being that should one not wish to take that road , which can often prove dissatisfying , then staying with one designer , one manufacturer , might prove to be the considered way to avoid expensive and time consuming experimentation and sometimes frustrating disappointment .

 

[dan31]

My Nagra PL-L has 12 db of gain and is single ended. 3 tubes so it’s easy to try different tubes. Look for a used unit and tweak like John recommended. Hard to lose money on an older Nagra.

 

[Audio Addict]

So what is your next step in this exploration instead of the Nagra HD?

 

[ct545i]

For what it may be worth, I own Nagra HD preamp, among some other Nagra gear. A couple of years ago I also owned VTL Siegfried II amps, which integrated very well with the Nagra HD preamp, there was no shortage of gain at all. I don’t think I ever needed to turn the volume past 12 o’clock position. The system sounded great.

HV was an update Nagra had done a few years ago to the original design, which was a matter of swapping a couple boards inside the HD preamp, an upgrade I was able to perform on my own after getting the kit from Nagra, which at the time cost $2000, if I remember correctly. So, non-HV version of the preamp can be easily upgraded.

 

[Holmz]

Jeeezuzzz … How difficult is it to comprehend ?!?! … For the most part designer’s of audio equipment factor in a fundamental circuit and component synergy between the units that they end up putting into production … Sometimes those design parameters such as gain , connectivity , etcetera are symbiotic between their component parts … Ergo If you want a Nagra Pre Amplifier pair it with a synergistically matched Nagra Amplifier , Same goes for Atma-Sphere , Robert Koda , Aries Cerat , Kondo, NAT….Ad Infinitum !

Ok - it seems harder to comprehend that you intimate…
How is one supposed to infer from the marketing that the preamp is solely acceptable for use with a Nagra amp?

Nagra's marketing info is pretty bullish "...output impedance is as low as 0.2 Ohm so that you can drive any amplifier on the market."

The use of the word “any”, seems to open the synergy to include everything?
(Or how am I supposed to infer synergy?)

 

[Holmz]

@SuperDave , @jfrech , @ct545i what are you all running in terms of power cords into your preamps/power supplies?
Some standard job, some old one laying around, or ???

 

[ct545i]

Holmz, I use fairly standard power cables or lower/mid grade Transparent.

 

[KeithR]

Just ask Renee at Nagra.

What’s missing here is that gain is for an entire system.

 

[SuperDave]

@SuperDave , @jfrech , @ct545i what are you all running in terms of power cords into your preamps/power supplies?
Some standard job, some old one laying around, or ???

Holmz,
I'm currently using Transparent Gen5 Reference XL PCs. I've tried a few others but its not a fair assessment using an all Transparent loom. I'm interested to try Siltech PCs that my dealer carries, Jfrech and I use the same dealer, their systems are my reference.

Dave

 

[microstrip]

(...) Nagra's marketing info is pretty bullish "...output impedance is as low as 0.2 Ohm so that you can drive any amplifier on the market." (...)

(...) The use of the word “any”, seems to open the synergy to include everything?
(Or how am I supposed to infer synergy?)

Not IMO. After a comment on output impedance "drive" just means "supply current". Nagra are stating that the HD reference HV can drive amplifiers with any load impedance, even very low. It would be a great preamplfier for the Marantz Project T1 (1 kohm input impedance) that none of my tube preamplifiers could drive. It was the main reason I did not keep it.

Remember that Nagra roots were in the professional audio!

 

[jfrech]

@SuperDave , @jfrech , @ct545i what are you all running in terms of power cords into your preamps/power supplies?
Some standard job, some old one laying around, or ???

I have Transparent Opus power cords on my front end equipment (HD Phono/Pre Ref DAC) all into Transparent Opus Power Isolators. Using Siltech Master Crown to power my HD Amps