Hi,
I'm trying to understand how the whole stuff works.
Sorry about that, but to do that I'm using a simulator (less danger and less smoke).
Let's have a look on the original Pass design for "Aleph 5": http://www.kk-pcb.com/a5serv.pdf that I have reproduced this way:
My question is threefold and always related to the C5 capacitor.
I'm trying to understand how the whole stuff works.
Sorry about that, but to do that I'm using a simulator (less danger and less smoke).
Let's have a look on the original Pass design for "Aleph 5": http://www.kk-pcb.com/a5serv.pdf that I have reproduced this way:
An externally hosted image should be here but it was not working when we last tested it.
My question is threefold and always related to the C5 capacitor.
- My simulations says that the input impedance on the XLR+ and XLR- is very different: 14.7kOhm and 5.3kOhm, respectively. Is this a "fake" result or it's real? and, if it's real, does it have any consequence on the SQ?
- If I replace C5 by an appropriate resistance I can get the two impedance's identical. For sure I have to recheck the OFFFSET and, to get the original gain, I need to raise the NFB resistance R7.
- The "Aleph" architecture is said to be "capacitor free": is anybody worried by the presence of C5 on the XLR- line?
Sorry about that, but, as I mentioned, this is the ORIGINAL schematics: https://scontent-mxp1-1.xx.fbcdn.net/v/t1.0-9/49533919_10156100077712709_2025601096138883072_o.jpg?_nc_cat=109&_nc_ht=scontent-mxp1-1.xx&oh=58942bbe9e8fdd1e6085eebee7f4b5f7&oe=5CC5D6BA.
Perhaps there is something better, among the many schematics I could find on the web. But, who knows?
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My mistake, thanks.
Now the two impedance's are 10.9kOhm and 9.1kOhm.
Let me guess that I should be satisfied.
But ... a huge capacitor on the XLR- line doesn't worry you?
Thanks
I believe I already pointed you to my Babelfish J thread , where you can see what worries me 
anyway , Aleph series was , in general , very successful series of amps , primarily due to sound quality , exquisite craftsmanship and longevity ........ which means that many satisfied customers didn't had nothing to worry about
suddenly , there we are , Greedy Boyz and Grand Tweakers , having doubts about Papa's constructions
if you're worried with that capacitor - just short it ; but only after you make entire amp and prove with DBT that you're able to hear when it is in circuit
anyway , Aleph series was , in general , very successful series of amps , primarily due to sound quality , exquisite craftsmanship and longevity ........ which means that many satisfied customers didn't had nothing to worry about
suddenly , there we are , Greedy Boyz and Grand Tweakers , having doubts about Papa's constructions
if you're worried with that capacitor - just short it ; but only after you make entire amp and prove with DBT that you're able to hear when it is in circuit
Me, I would only to be helped to understand.suddenly , there we are , Greedy Boyz and Grand Tweakers , having doubts about Papa's constructions
I have no faiths or misconceptions.
No phase rotations on T2 (see my schematics)? tell me that and I shall trust you.
Sorry, but I don't understand your naming convention: long tailed pair - Google Search
An externally hosted image should be here but it was not working when we last tested it.
@10kHz
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Just invest some time at my last picture.
No phase shift? an artifact of the simulator? please tell me!
Even if I worked on that only with tubes I guess I know what a LTP is.
I'm not following you there ..... each time I looked at LTP , it did what is expected to do ......
if you can't see it , it's something wrong with your understanding ...... or sim approach or whatever
I can't force you to understand , especially I can't explain better than it's explained in linked youtube video
if you can't see it , it's something wrong with your understanding ...... or sim approach or whatever
I can't force you to understand , especially I can't explain better than it's explained in linked youtube video
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