Since you ask me, it is my experience that the Aleph P sound does vary with
the settings of the gain controls, and it seems that the most popular
position for those is about 3 o'clock, so I would try playing with that.
Also it makes a difference whether you are running balanced or unbalanced
on the inputs and/or outputs, and if you are running unbalanced on any input
it's crucial that you use the jumpers on the XLR connectors.
Those aside, it's always possible that the combination of Aleph P and the
amp is simply not to your taste, in which case I think you want to try
listening to other preamps and see what you get.
Thanks Mr. Nelson
I will try that. I have to use the jumpers inside the pre to reduce the gain. So the 3 o`clock will be more possible at normal levels.
I’m not using unbalanced inputs, only balanced. So no problem here. All jumpers in place.
And I will also check on the new line of XP-10 or XP-20.
Hi guys. I found my problem. I forgot that I did make Changes on my DIY speakers long time before I buying this AMP the Zobel-network in my Middle Driver. I did change is back and I was sounding that this influenced my speakers that much that the ware dead sounding before that. Now the bloom is back. Not the bloom as my Aleph X , but the sound is already better then my AMP Aleph x. More accurate and neutral! His was what I was looking for!
I`m experiencing that the pointer moves 1mm if the loudness on my speakers is almost to the max. And this pointer goes backwards. It this causing by my speakers or power supply!? I think my speakers needs more watts, or I'm wrong? 89dB efficient. Also I hope this will not degrade my experience on my LP. If happens only on very loud listening that I usely do not do. Do I need more powerful AMP ?
I found now that is even moves when there is no sound reproduction. Also backwards.So I think it's my supply of current.The current vary is 236.2V - 238.5V
I`m experiencing that the pointer moves 1mm if the loudness on my speakers is almost to the max. And this pointer goes backwards. It this causing by my speakers or power supply!? I think my speakers needs more watts, or I'm wrong? 89dB efficient. Also I hope this will not degrade my experience on my LP. If happens only on very loud listening that I usely do not do. Do I need more powerful AMP ?
I found now that is even moves when there is no sound reproduction. Also backwards.So I think it's my supply of current.The current vary is 236.2V - 238.5V
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I can still invest more and get the bigger 100.8 But is it worth the money!?
I'm aware of that. I formulated it wrong. Question should be it ist necessary to upgrade to bigger one in my case. And that are the sonic differences 60.8 vs 100.8 ? [emoji57]
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I dont know if ist worth the Money.
But if i ever come in a Situation like yours
I would Keep the 60.8 the $$$$difference to 100.8 i would invest in a travel like in Picture
If some Money is left i would buy some cd`s and listen to them on the 60.8 when i`m back from traveling
But if i ever come in a Situation like yours
I would Keep the 60.8 the $$$$difference to 100.8 i would invest in a travel like in Picture
If some Money is left i would buy some cd`s and listen to them on the 60.8 when i`m back from traveling
Attachments
I dont know if ist worth the Money.
But if i ever come in a Situation like yours
I would Keep the 60.8 the $$$$difference to 100.8 i would invest in a travel like in Picture
If some Money is left i would buy some cd`s and listen to them on the 60.8 when i`m back from traveling
....got my vote...or you could do one of those fantastic safaris in Botswana....
You are right So I now have another Trip in mind. I will have for extra money a Time Machine according Pass Labs.
On Friday i will have for 2 days Pass Labs XP-30 for audience. I leave it on for a night, and on Saturday I want to be in another world
I`ll report what I think about it after that.
So I now have another Trip in mind. I will have for extra money a Time Machine according Pass Labs. On Friday i will have for 2 days Pass Labs XP-30 for audience. I leave it on for a night, and on Saturday I want to be in another world
I`ll report what I think about it after that.
Now that Nelson has revealed at least one form of cascade local feedback in the VFET p2 thread, are you able to say whether your approach turned out to be the same or something different? Just curious.
Ian
Lynn has come up with several useful connections. The one I put in the Sony
pt 2 is just about the simplest possible.
I think the key item is to realize that this form of local feedback is best used in
modest doses, primarily because it also makes the input stage work harder
for a given output. We see this in the revised resistor values, where it
was decided that 22K feedback resistors sounded better than 10K, and
higher Vas resistive loading allowed more impedance degeneration on the
global "current" feedback.
pt 2 is just about the simplest possible.
I think the key item is to realize that this form of local feedback is best used in
modest doses, primarily because it also makes the input stage work harder
for a given output. We see this in the revised resistor values, where it
was decided that 22K feedback resistors sounded better than 10K, and
higher Vas resistive loading allowed more impedance degeneration on the
global "current" feedback.
...
I think the key item is to realize that this form of local feedback is best used in modest doses, primarily because it also makes the input stage work harder for a given output.
...
By "work harder" Nelson means that any open-loop gain (OLG) that is devoted to the cascode feedback is "stolen" from the global feedback. If you can increase the front-end (FE) OLG to compensate for that used for cascode feedback, then all should be OK. In practice, if the output stage (OS) has relatively low input capacitance non-linearity then there is little advantage to using cascode feedback, other than possible stabilization of the FE output offset voltages.
One way to increase the input stage OLG is to reduce the values of the feedback and shunt resistors (R23 and R24 in the Sony VFET p2). Another way is to reduce the JFET bias current by using JFETs with lower Idss or by adding JFET source degeneration resistors, requiring and increase in the effective drain load resistance in order to bias the 2SJ313/2SK2013 FETs.
The downside to increasing the input stage OLG is additional nonlinearity by requiring more "work" from the JFETs. Does the local cascode feedback around the input stage compensate for that added distortion and MORE?
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The Cascode Feedback [CF] innovation by Mr. Pass also grants the front end [FE] of Sonypt 2 a Schade-Effect or triode-like properties. The signature of Schade Effect is negative feedback which emanates from a junction of high output impedance [opposed drains of FE Mosfets/2.2K load] and terminates into a low impedance port. Thus this amp is triode from its FE to its power output. Absent CF, the resultant FE defaults to a plain cascoded BA3 FE; which has instead pentode output properties.
Thanks for all the replies!
Personally I prefer to use as little feedback as I can get away with in general and local over global, hence my interest in the cascode feedback. It also seems to me that this form of cascode feedback has the desirable property that it effects the FET providing most of the gain and hence most of the FE distortion (local degeneration aside). Presumably there is also a benefit deriving from the reduced output impedance of the FE for driving the output stage capacitance.
As with all these things, there are many variations and options. Building and listening it seems is the only way to decide on which is better or preferred
Ian
Personally I prefer to use as little feedback as I can get away with in general and local over global, hence my interest in the cascode feedback. It also seems to me that this form of cascode feedback has the desirable property that it effects the FET providing most of the gain and hence most of the FE distortion (local degeneration aside). Presumably there is also a benefit deriving from the reduced output impedance of the FE for driving the output stage capacitance.
As with all these things, there are many variations and options. Building and listening it seems is the only way to decide on which is better or preferred
Ian
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