If I stay with Jadis I would get JA120s and use EL34s.
If I don't stay with Jadis I would try something more exotic.
Nagra HD Preamp Versus Aries Cerat Incito S Preamp
- Thread starter Ron Resnick
- Start date
If I don't stay with Jadis I would try something more exotic.
Totally agree with you. At the time I had a friend with a Callisto/Io both with dual power supplies and fully NOS tubed out. I loved his system and his sound. But the Nagra PL-L with just 3 tubes and a simplicity of circuit just has something beguiling along with 3 less powercords/shelves/chassis and associated heat.
I might suggest you check out the Nagra Classic Preamp. It's quite special and you can add matching PSU later if you want for improved performance. If you try this make sure you have the balancing output transformer option for your VTL's and the proper fully balanced XLR cables. (Ditto if you try the HD Preamp, you'll want the balancing output transformers for your VTL's)
Thank you.
Is Nagra HD a natively differential circuit? True balanced input to true balanced output with true differential circuit in between?
Hi no-it is a single ended gain stage. But has optional input and output transformers for either balanced sources or balanced amps.
I found fully balanced sources such as my prior dCS Vivaldi preferred the input transformers. My current Nagra Ref DAC is inherently singled ended, I tried it both ways and prefer the input transformers removed. I've done the same on the output, and prefer using the balancing output transformers with my amps.
Thank you for explaining.
This is a separate point, but it is very interesting that you prefer the balancing input transformers and the balancing output transformers over the single-ended inputs and outputs in your system.
Rightly or wrongly my operating theory is that -- absent a noise or grounding problem -- nothing good comes from wrapping transformers and balanced connections around a natively single-ended circuit. So it is very interesting to me that in practice you still prefer going through the unbalancing and balancing transformers.
Transformers when done properly can be nice to have. In the Nagra the output transformers were used to drive amplifiers with a balanced design.
In your case Ron, balanced to the VTL and switch to SE for the Jadis. Using the SE output the signal comes straight from the output tubes.
I get the purity of design ethos for SE designs and with a complete SE system it makes sense to keep it simple.
In your case Ron, balanced to the VTL and switch to SE for the Jadis. Using the SE output the signal comes straight from the output tubes.
I get the purity of design ethos for SE designs and with a complete SE system it makes sense to keep it simple.
Last edited:
I thought dan31 said it well above. And if you have a balances and a se amp, this gives you the best of both worlds. Nagra winds their own transformers and apparently have deep expertise here. In the case of the HD preamp, it's not using resistors or pots, but a variable transformer for the volume. In my Nagra Ref DAC, they are using transformers for gain before the tube stage.
One point of correction, I preferred the input transformers with my fully balanced dCS dac. With my single ended Nagra dac, I prefer the input trannies out. (both configs I am keep the balancing transformers in for the output to my amps).
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.
Hi Marty. I took delivery of mine on New Years Eve. So I've had it a little over a month. It replaces my dCS Vivaldi Apex DAC/Upsampler/Clock. I kept my Vivaldi Transport. In a nut shell...it's amazing. Let me know what questions you have...ok to PM if you want.
Does anyone know the specification of the Nagra HD preamp regarding gain? Oddly, I cannot find it on the Nagra website specifications list.
The owner of the HD preamp I was considering buying indicated that he thought it was only 8dB or 9dB of gain (which, if true, is not enough gain for the gain structure of my system).
The owner of the HD preamp I was considering buying indicated that he thought it was only 8dB or 9dB of gain (which, if true, is not enough gain for the gain structure of my system).
"Maximum gain is +5.6dB (RCA in/XLR out) or –0.4dB (XLR in/out) and is unaffected by the ‘Studio’, ‘High’ and ‘Low’ input settings on its rear. "
From https://www.hifinews.com/content/nagra-hd-preamp-preamplifier-lab-report
Nagra does not list gain in their specifications.
Microstrip, I guess that they meant to say was it's +5.6db from 1v, 2v or 10v. So obviously +5.6db is louder from 2v setting vs 1v?
I have my HD Pre and Amp set at 1v. Never go past about 2 o'clock on the volume control....so in my context I have more gain than I need at the lowest output voltage setting.
Here is some more info from Nagra:
"The HD PREAMP has the best specifications ever achieved by any tube preamplifier, a floor noise lower than -160 dB and 5 Hz to 200kHz frequency response with perfect phase integrity. The impedance input is 50 k Ohm and the output impedance is as low as 0.2 Ohm so that you can drive any amplifier on the market.
The HD PREAMP is able to accurately reproduce a square wave at 16 Hz."
Many preamplifiers have excessive gain - we have to use them around 10-11 o'clock. It looks your Nagra is being used at an excellent setting. As far as I remember the output impedance of your preamplfier depends on the volume control level, being minimal at maximum level, as could be expected from a stepped output transformer.
Thank you for this. That's even lower than my seller thought the gain is.
Well I'm sure as heck glad I didn't get involved with the Nagra HD preamp! Only 5.6dB of gain is pretty wacky from a flagship preamp marketed as a general purpose line stage.
Nagra should market this explicitly as a "low gain line stage." No wonder they don't disclose in their spec sheet the gain -- a rather important specification for a line stage pre-amplifier!
The only other time I saw a gain spec this low for an active line stage preamplifier was my Hegel P30A with only 5dB of gain for a solid-state preamplifier. Unsurprisingly, Hegel, like Nagra, did not include this spec in its list of specifications for a product advertised as a general purpose line stage preamplifier.
In fact, most other amplifier manufacturers should mark their preamplfiers as "having excessive gain" . Some people say that preamplifiers have in general excessive gain because ignorant customers usually want to compare equipment at the same volume level and put the buttons at the same position when comparing.
Manufacturers knew that in such case louder will probably win! Another reason is that simple circuits often sound better with a gain of 12 to 15dB - we accept such high gain but have attenuate signals at the volume level. At what volume level (position) do you typically use your preamplfier?
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?In fact, most other amplifier manufacturers should mark their preamplfiers as "having excessive gain" . Some people say that preamplifiers have in general excessive gain because ignorant customers usually want to compare equipment at the same volume level and put the buttons at the same position when comparing.
At what volume level (position) do you typically use your preamplfier?
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.
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.
Hi Ron did those two 8 db gain preamps have multiple output voltage settings? 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...
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."
Final point, I am pretty sure the output transformers deliver another +6db of gain....which is why I am at the 1v setting ....
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
Thanks to 213Cobra for this information.
Yes. This matches my experience. You can vary the input gain, the output gain for max flexibility.
(The HV nominclature stand for High Voltage...Nagra updated the HD Preamp a few years ago, it was new card going into the power supply chassis if I remember correctly....)
Similar threads
 | Steve Williams Site Founder | Site Owner | Administrator |  | Ron Resnick Site Owner | Administrator |  | Julian (The Fixer) Website Build | Marketing Managersing |