Ron's Speaker, Turntable, Power and Room Treatment Upgrades
- Thread starter Ron Resnick
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Nice toy, Ron!
Glad to read that you got it sorted out. Being forced to let a vehicle sit that long can lead to a costly tear down and rebuild in order to get it back into peak condition. I hope your having fun running in canyons once more.
Dan
Glad to read that you got it sorted out. Being forced to let a vehicle sit that long can lead to a costly tear down and rebuild in order to get it back into peak condition. I hope your having fun running in canyons once more.
Dan
It turns out that the solid-state Gryphon amplifier (10kohm input impedance) built into the bass towers of my Gryphon Pendragon speakers are wired in parallel with the external amplifier selected by the user to drive the separate ribbon panels (45kohm input impedance). I don’t know the underlying electrical reason, but this parallel load creates a heavy load on the line stage preamplifier. I believe Gryphon recommends a line stage with an output impedance of less than 100 ohms and, preferably, less than 50 ohms. The lower the output impedance, the better.
Further, my line stage will be driving 17 meters of interconnect. This long length of interconnect apparently puts an additional load on the output stage of the line stage. Especially with these factors added together I am wondering if the Aesthetix Callisto line stage with an output impedance of 350 ohms will not be ideal for my peculiar application.
Should I be concerned that my particular situation will place too heavy a load on the Callisto, with the sonic results that I may lose dynamics and high-frequency “sparkle”?
Further, my line stage will be driving 17 meters of interconnect. This long length of interconnect apparently puts an additional load on the output stage of the line stage. Especially with these factors added together I am wondering if the Aesthetix Callisto line stage with an output impedance of 350 ohms will not be ideal for my peculiar application.
Should I be concerned that my particular situation will place too heavy a load on the Callisto, with the sonic results that I may lose dynamics and high-frequency “sparkle”?
There are numerous members qualified to answer technical questions...the only point i would make is if you do elect to move away from Aesthetix...the good news is the VTL 7.5 MkIII output impedance looks to be around 25 ohms with a peak of 150 ohms at 10hz.
BTW, since this is about your system...i note that both Roy Gregory and Marc Michelson appear to rate your Siegfried IIs as their favorite amp...period. the top of the heap.
BTW, since this is about your system...i note that both Roy Gregory and Marc Michelson appear to rate your Siegfried IIs as their favorite amp...period. the top of the heap.
10k input impedance is pretty darn low, that's probably why they are suggesting what they are... not how many pieces of equipment can be driven by a preamp.
You could always insert a buffer between the gryphon amps and whatever preamp you're using, then you have nothing to worry about as far as what preamp you plan to use.
You could always insert a buffer between the gryphon amps and whatever preamp you're using, then you have nothing to worry about as far as what preamp you plan to use.
Unfortunately it is not yet a technical question - we do not have technical data enough to risk an opinion. And even after we have all the data it is not possible to assure 100% on the matching. IMHO only experience will tell it.
I have said it before - most of the time buying high-end needs some in room experimentation. Particularly when the room is still being finished and the speakers have never been measured.
Seriously you can use the preamp you want if you just use a buffer. I'd even consider putting one together so you could not have to change plans.
Unfortunately it is not yet a technical question - we do not have technical data enough to risk an opinion. And even after we have all the data it is not possible to assure 100% on the matching. IMHO only experience will tell it.
I have said it before - most of the time buying high-end needs some in room experimentation. Particularly when the room is still being finished and the speakers have never been measured.
This indeed may be a bit tricky for a tube pre. I agree you need to try things out given the unique challenges here, but you can build a plan to start by AB-ing a backup with lots of capability in this regard to create a benchmark to see if the Callisto is up to the task. A starting point to consider might be something like the Soulution 725. Output impedance is 2 ohms and it is designed to drive the 2300 ohm input impedance of the 701s. It is extremely capable when it comes to this kind of an application. You may or may not prefer the sonic signature, but regardless, in your application I think it would give you a benchmark for dynamics that you could use to gauge the system performance versus the Callisto or other candidates as you evaluate. Just a thought...
Or perhaps just ask the designer of the active speaker crossover to increase the input impedance to 100 kohm. Perhaps it can be done very easily.
40kohm isn't so bad.
But the same situation holds true, where if you're worried about driving multiple amps, just use a buffer for the subs.
Increasing the load is a way to get a bit more of stable improvement, but may not be easy for some reasons.
But the same situation holds true, where if you're worried about driving multiple amps, just use a buffer for the subs.
Increasing the load is a way to get a bit more of stable improvement, but may not be easy for some reasons.
Jim White very kindly focused on this issue immediately when I raised it with him here in Munich, and he suggested that he can make a very simple transistor buffer circuit to solve the problem.
I said in reply that then we would be adding a transistor in the signal path of an all tube design, as opposed to me using a hybrid preamp such as the VTL 7.5 Series III. Jim replied that that is true, but at least with the Callisto I would have an all-tube circuit handling the gain stages with the outboard transistor only for the buffer.
I said in reply that then we would be adding a transistor in the signal path of an all tube design, as opposed to me using a hybrid preamp such as the VTL 7.5 Series III. Jim replied that that is true, but at least with the Callisto I would have an all-tube circuit handling the gain stages with the outboard transistor only for the buffer.
Thank you for the suggestion, but it is not easy with the speakers being 10,000 miles away.
Thank you, LL21. I am excited about the amplifiers, and I think it is funny that after a two year global amplifier search I came full circle!
I know very little about the hybrid TL-7.5 Series III. Have you auditioned it?
Ask the designer to come to your place. They will do it for you because they care about you getting the best sound out of their speakers. You are a prominent audiophile. Your feedbacks are very important to them. These speakers are not low dollars. My speakers designer will even come see me again to further fine tune after the AE show.
Kind regards,
Tang
You don't have to run the buffer between the preamp and your amp for the fullrange towers. You can just do it for the bass towers.
I have not heard it...but read only good things about it. superlative things actually. And there are certainly members here who strongly advocate using pre/amps from same designer. For these reasons plus your impedance question, certainly seems like an option.
But it is effectively in the signal path to the ribbon panel amplifier because the bass amplifier electronics pass the full range signal through and out to the ribbon panel amplifier.
It definitely is an option. I, too, believe there’s some value in matching the preamp to the power amp.
Given that Gryphon is designed with all solid-state in mind having a transistor output stage in the line stage may be a small philosophical price and a small sonic price to pay to be completely comfortable that the line stage can easily drive all of the downstream amplification electronics.
No. The fullrangers are fed by the amplifier. The bass tower is fed by the buffer from the preamp. They would be in parallel - the bass towers and fullrange amplifier/s, from the preamp.
The bass towers don't even have taps for the speakers. They are made so it's possible to feed in and out of them, but there is no requirement or good reason to do that in particular.
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