I know Blue here highly rates Duos on Audiopax, the only amp he would swap to from his own design 45 monos. Keith should get a good comparator versus his London demo w Nagra.
Actually, I found a very nice little amp from WLM (made by trafomatic ) that is quiet on my 110db mid/high horn driven directly. There is a bit of hiss but not audible once away from the horn. The Mastersound i have is not quiet enough for this application. The amp is PP Class A triode without feedback and sounds very good used from 700hz and up. The new price of the little amp was 2800 euro only.Mallen, hum evident thru horns is one of the reasons that despite being so drawn to the idea of horns ownership, I'm struggling to justify the practicality. My Zus are specced at 101dB eff, but prob closer to 99dB, and even at 6-8dB less efficient than Duos, I'm aware of noise from my Nats 70W 211s at 12-18" from my Zus. It would be a massive risk to assume that could ever be acceptable going to something like Duos.
Unfortunately the budget for Duos or any reasonable horns would totally clean me out w no funds left for an amps upgrade.
A shame, horns talk to me in lots of ways. But if a tube amp like Nagra way quieter than my Nats is "audible" thru yr Duos, this doesn't bode well for my situation.
Moral on horns? You can't compromise at all.
I did this whole setup for < 5k euro.Brad, I already go into more debt than I'm comfortable with buying any decent horns... and my GF will have her arms even more tightly folded...if I talk about new amps as well. But good suggestions.
Ok, I guess you are doomed to overpay...or stick with Zu .I'm not seeing any decent horns for much less than €30k
Pr Liszts for sale at €40k but can't fit them in
Amps to match or beat my Nats won't give me change from €10k
€40k minus any funds from sale of Zus and Nats is more than I can afford
Please don't come back to me w ideas on any DIY or aesthetically challenged or bass light horns, my Zus won't move aside for them
Ok, I guess you are doomed to overpay...or stick with Zu .
There are a nice set of G1 Trios for 17.5k though and some Duos with upgraded subs for10k.
No doubt I would appreciate Blue58s Duo Omega. I'm a fan of all the Duo Omega line especially when set up well with excellent electronics.Mallen, you would feel pretty positive twds Blue58 if you could hear what he has achieved. He has the Duos Omegas, and over the 5 years I've got to know him and visited his system, he has wrung every last drop out of them.
I have my eye on a few horns, incl Duos Omegas. My bigger issue is the fact, like going to Apogees, that such a radical change of direction necessitates a major change of amps, and I can hardly afford just the horns. I am not going to swap a highly evolved, optimised and synergistic Zu/Nat combination that I've spent 5 years and £30k on, for potentially stellar horns and a substandard but cheap as chips tube amp.
I am investigating a potentially very sweet combination of fascinating horns and amps I know will work w them. But this is touch and go financially.
Your hum could be power related. I have had some amps with hum issues only for them to vanish when I took the amp somewhere else. Ground loops can also affect each piece in a chain differently.Hi Spirit -
yes - i can see that 70 watt NAT amps might be too noisy thru 107 DB speakers. That said, I tried the ARC GS150 8 KT150 tube with my Duo's and it was dead quiet, so one never knows. The Nagras have a 100 db S/N spec, so the hum could be due to they are out of spec. The Canadian dealer I bought them from used them as Demos with 103db Acapella horns and claims to have never heard any hum.
Have you thought about taking your NAT 211s to an AV dealer near you? Or maybe Blue58 would be willing to let you try them with his Duos? You'd need to make sure the pre amp was compatible with your NATs , so it might not be so simple, but would at least confirm whether they were compatible or not.
NAT gear has very high gain in general (my Plasma preamp was almost unusable with some amps due its gain). Is there some way to reduce it? Sometimes an input tube swap to something similar but with less gain can work...but you have to know which tubes work and don’t. Maybe a call to NAT. I bet if the gain was lower most of the noise issues would vanish.I really don't want to impose on his system, which is JUST SO, perfectly set up. More likely he'll lend me his refurbed spare set of 45s and Java passive pre to help on any home trial of horns.
The chance of sorting my Nats out is slim to zero. I know of only one repair shop that is familiar w these fiendishly tricky beasts. Additionally this may be a 211s issue, but finding alternative quads of 211s is trickier and trickier. With no guarantee even this sorts my issues. New preamp 6n23p tubes have helped a lot to quieten things down. But not to the point where the Nats are reliably quiet enough to use w horns. And since the synergy w Zus is so magical as is, I have to weigh up the pros and cons of replacing a predictable and engaging sound with a radical new direction incl brand new horns AND amps. And find the cash.
My understanding was that AG always used the Beyma CP380m compression driver for a tweeter. The photos on AGs website now show the tweeter and it is clearly a Beyma driver. This driver has been around since early 2000s if not earlier...perhaps they used something else in the earliest models?If you buy G1 Trios or Duos, just make sure they have the Omega upgrade (new tweeter/mid range drivers , internal wiring and CPC crossovers). Omega upgrade was a significant improvement in speed and resolution over my original non Omega Duo.
Non Omega G1 Duos were quite available for 7 to 10k USD a few years back. The Omega upgrade kit for G1 Duos is no longer available from AV. I bought the last kit in 2015 and listened to my upgraded Duo's with additional separate subs for about 3 mths with the upgrade until my Mezzos came in.
I sold my upgraded Omega G1 Duos for $15k US in 2015, and best price I've seen here in US for G1 Omega Duo was $11k years ago during the recession. A good condition G1 Duo Omega coupled with a very separate fast subwoofers to extend below the Duo subwoofer limit of 23Hz is pretty hard to beat.
I think you misunderstood. The input/driver tubes are what determine the gain of your amp. It might be possible to swap those for something with lower gain. I think NAT was using 6N2P tubes so there might be another, very similar tube with less gain...or not. If your 211s are in good working order they will likely not improve things by getting new ones. Do you know the driver tube type?Brad, it's not hum that's the issue, but hash/tube rush. Changing the smaller tubes in pre has helped, but it's nigh on impossible to change the 211s in the monos (lack of choice, difficulty in biasing, potential waste of £2k if don't check out).
Additionally, Nat are useless on comms. A lack of English and replies that are very late, non existent, or brief to the point of hopelessness, sums up their customer service.
No, a serious horns purchase is gonna demand a totally new amps setup. The good news is I pretty much know what two options I would consider.
Plenty to cogitate on.