you must try it and decide is it worth ;
someone else's F5/spks/room/ears/brain combo must not be analog to yours
start in small increments - few db of difference
someone else's F5/spks/room/ears/brain combo must not be analog to yours
start in small increments - few db of difference
If you try this, it will be a learning experience.
Trust your own ears, and don't be influenced by what other people think.
Remember 100 Ohm is enough to get voltage clipping of the amp, so you don't need to increase it by much, unless of course you like the sound of clipped music.
Or is it you just don't like turning the volume pot too far.
Trust your own ears, and don't be influenced by what other people think.
Remember 100 Ohm is enough to get voltage clipping of the amp, so you don't need to increase it by much, unless of course you like the sound of clipped music.
Or is it you just don't like turning the volume pot too far.
Qoute:
When anyone starts talking about more power, that
tends to steer them away from Alephs. It's not like it
can't be done, but usually it's more effort than you
probably want, and the performance will not be as
dynamic as many people expect from higher power amps.
Perhaps it's time to consider a high wattage DIY project.
Previously there was the "Pass Monster", instigated by some
member here, but they pooped out on it.
I guess I have to do it myself - the guru's work is never
done....
Just 2 3 weeks ago I was sort of asking same question on whats what and wich ?
In his poste Nelson Pass wrote
Quote:
I should fix that one one of those days
Dont even think about: "here we go he is after browny points " Browny are boy scouts over here in the UK.
I am not that kind of person
314.... good reasons why was also meant to collect sugestions on how to improve the A75
So if I may few things came up
1)F5 sounds fantastic
2)2SJ109 are a real pain to find
3) we like more power even if we may not need it
Think we could agree on those points?
There are few things more that may be prattical
I have seen a few mods and discussions relating to power suply voltagge and transformers.
I was thinking that if the suply rails are designed around 55 nominal voltagge of the secondary then in the US you wont need a transformer as there is one stuck on a telegraph pole not to far away.
Here in the Uk we have loads of transformers that we use for our power tools that are again 55 55 secondary I got a 3 KVA in the loft doing notthing.
I could buy loads of milli farads with the money I would save + no noise, no magnetic interference save space and weight.
So then what about a transformer less amp?
Again from reading the various treads cooling has been an issue to the point that I was thinking how lucky I would be to live in Australia I would just had to T off the air conditioner pipes and hey presto water cooling for free.
Need to remmber to look in the loft for the Deumidifier I use to use in the flat before I moved.
Maybe this is worth a patent Use of your old deumidifier to cill the amps
Sorry for being a bit long winded I get like that when I am Exited.
To keep this prattical what would be possible tu use there are loads of new types of Mossfets. Papa got the monopoly on TO3 what about new styles any god one out there whit loads of capacitance spoiling the fun is there any way around this?
When anyone starts talking about more power, that
tends to steer them away from Alephs. It's not like it
can't be done, but usually it's more effort than you
probably want, and the performance will not be as
dynamic as many people expect from higher power amps.
Perhaps it's time to consider a high wattage DIY project.
Previously there was the "Pass Monster", instigated by some
member here, but they pooped out on it.
I guess I have to do it myself - the guru's work is never
done....
Just 2 3 weeks ago I was sort of asking same question on whats what and wich ?
In his poste Nelson Pass wrote
Quote:
I should fix that one one of those days
Dont even think about: "here we go he is after browny points " Browny are boy scouts over here in the UK.
I am not that kind of person
314.... good reasons why was also meant to collect sugestions on how to improve the A75
So if I may few things came up
1)F5 sounds fantastic
2)2SJ109 are a real pain to find
3) we like more power even if we may not need it
Think we could agree on those points?
There are few things more that may be prattical
I have seen a few mods and discussions relating to power suply voltagge and transformers.
I was thinking that if the suply rails are designed around 55 nominal voltagge of the secondary then in the US you wont need a transformer as there is one stuck on a telegraph pole not to far away.
Here in the Uk we have loads of transformers that we use for our power tools that are again 55 55 secondary I got a 3 KVA in the loft doing notthing.
I could buy loads of milli farads with the money I would save + no noise, no magnetic interference save space and weight.
So then what about a transformer less amp?
Again from reading the various treads cooling has been an issue to the point that I was thinking how lucky I would be to live in Australia I would just had to T off the air conditioner pipes and hey presto water cooling for free.
Need to remmber to look in the loft for the Deumidifier I use to use in the flat before I moved.
Maybe this is worth a patent Use of your old deumidifier to cill the amps
Sorry for being a bit long winded I get like that when I am Exited.
To keep this prattical what would be possible tu use there are loads of new types of Mossfets. Papa got the monopoly on TO3 what about new styles any god one out there whit loads of capacitance spoiling the fun is there any way around this?
Hi Russel
Agree with you and had a few treads going in this regard.
Nelson Pass replied there that is only offering was the A75
he wrote :
Quote
I should fix that one one of those days
Not here to get Browny points (Browny = Boy Scouts) I say lets join forces and for those going to the burning amp festival please dont forghet you Hary Krisna bels and start dancing around Papa and sing Oh Yes you shuld
We like to have more power even if we dont rely need it.
While reading warious treads few things came up.
1)We like more power
2)2sj109 are a pain to find.
3) the F5 sound fantastic
I think we can all agree on those.
I would suggest one more thing if Papa intend to gift has with a new design.
Design the amplifier with power suply rails of 55 55 volts
This way in the US you can use the transformer thats sit on the telegraph pole not to far away from your home (110 V Mains ) and here in the UK we can use safety transformers designed for industriall power tools.
Whith the money we save on the trafos we could buy loads of millifarads
There are loads of more advantages on a transformerless Amp no mech noise no mag field a 2% increase in efficency.
PS How do you use the Quote duda ( I am beter at changing the carbon brushes on a 1943 400Hp Stirling than using 486es )
PSS Hope that Nelson Pass does not mind the use of the Papa and such comments from same total Pain in the Woofer stranger. It is done with the outmost respect
Personaly if one deserves the Nobel prize Nelson is one
Hum maybe he does not like being asociated with the inventor of Dinamite
Agree with you and had a few treads going in this regard.
Nelson Pass replied there that is only offering was the A75
he wrote :
Quote
I should fix that one one of those days
Not here to get Browny points (Browny = Boy Scouts) I say lets join forces and for those going to the burning amp festival please dont forghet you Hary Krisna bels and start dancing around Papa and sing Oh Yes you shuld
We like to have more power even if we dont rely need it.
While reading warious treads few things came up.
1)We like more power
2)2sj109 are a pain to find.
3) the F5 sound fantastic
I think we can all agree on those.
I would suggest one more thing if Papa intend to gift has with a new design.
Design the amplifier with power suply rails of 55 55 volts
This way in the US you can use the transformer thats sit on the telegraph pole not to far away from your home (110 V Mains ) and here in the UK we can use safety transformers designed for industriall power tools.
Whith the money we save on the trafos we could buy loads of millifarads
There are loads of more advantages on a transformerless Amp no mech noise no mag field a 2% increase in efficency.
PS How do you use the Quote duda ( I am beter at changing the carbon brushes on a 1943 400Hp Stirling than using 486es )
PSS Hope that Nelson Pass does not mind the use of the Papa and such comments from same total Pain in the Woofer stranger. It is done with the outmost respect
Personaly if one deserves the Nobel prize Nelson is one
Hum maybe he does not like being asociated with the inventor of Dinamite
Hops
Duble post tought I lost the first one maybe pressed wrong button how would you delete the first one
Duble post tought I lost the first one maybe pressed wrong button how would you delete the first one
I have a sneaking suspicion that Nelson Pass made the feedback as is for a reason. Perhaps I will get more gain but not the same performance. That gets me thinking about an Aleph, and then I get a headache. I'm going to listen to the F-5 for a while, very enjoyable as is.
Russellc
he put new toy in playground ( 'cause kids are always screaming for more ) ;
he never said " don't play with it"
choose your color for your favorite toy .....
😉
OK, shortly I will convert a set of Peter's boards already stuffed that I have in reserve to the altered feedback scheme for my next build. I dont suppose its possible to find a "tuff enough" pot to put there, allowing feedback adjustment?
By the by, which of these resistors are the ones to be changed?
Russellc
Attachments
I figured the trim pot was out, thanks for making that clear. Was that horse beaten in the F-5 thread? If so, I guess I went past that as theorectical stuff I wasnt ready for, as I was just then building F-5. I'll go back over it and find it, thanks again for the info. This was my first SS amp build! The only thing I hate worse than asking horse beating questions is doing something wrong without, then having to ask them as well as how to put smoke back in amp!
I'll get better.😀
Thanks again ZM,
Russellc
I'll get better.😀
Thanks again ZM,
Russellc
besides fun -that's main goal 😉
just ask ....... as you said - better to ask than sorry
Just so you're absolutely clear about this.
There are 4 resistors R5, R6, R7, R8 in parallel. The stock value is 100 Ohms each. This gives you 50 Ohms of effective resistance per feedback loop.
You could try replacing the 100 Ohms resistors with either 150 Ohms, 200 Ohms, or even 300 Ohms. This will give you effective feedback resistance values of 75 Ohms, 100 Ohms, and 150 Ohms respectively.
Do one channel at a time and compare the difference (ie listening test).
There are 4 resistors R5, R6, R7, R8 in parallel. The stock value is 100 Ohms each. This gives you 50 Ohms of effective resistance per feedback loop.
You could try replacing the 100 Ohms resistors with either 150 Ohms, 200 Ohms, or even 300 Ohms. This will give you effective feedback resistance values of 75 Ohms, 100 Ohms, and 150 Ohms respectively.
Do one channel at a time and compare the difference (ie listening test).
Hi Russellc
Hope this may help
From resistors in parralel formula RT=1/(1/r1+1/r2+1/r3
Then r3 = 1/RT-(1/r1+1/r2)
so if you need to drop RT from 50 oms to say 45 you need a 450 ohms resistor in parralel
I have a excell sheet that does the maths and Acad drawing but not a clue on how to put those here.
Can email if you like ..
Hope this may help
From resistors in parralel formula RT=1/(1/r1+1/r2+1/r3
Then r3 = 1/RT-(1/r1+1/r2)
so if you need to drop RT from 50 oms to say 45 you need a 450 ohms resistor in parralel
I have a excell sheet that does the maths and Acad drawing but not a clue on how to put those here.
Can email if you like ..
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