ppa ocxo under the hood

[nige2000]

my knowledge of ocxo is almost zero
i didnt probe it much yet as i spent quite a while trying to get the hood off without breaking it although more than once came close to throwing it pretty far
i assume the clocks and the oven is in the little tin dome thing and it does get hot like a 4 second hot
looks like its frequency is derived from a 10mhz clk

i dont see any interesting markings on any of the parts
i know its a bit rich coming from me but it looks a bit home brew

Very interesting that the frequency is derived from 10mhz - that would definitely be the cheapest way to do it. Take a look on ebay, there are loads of 2nd hand 10mhz OCXO's for sale. Could work out cheap to experiment and removing the lid might allow us to have dual power supply - one to the heater and the other for the crystal??

yea i had thought about the ebay ocxo's but decided i couldn't be bothered as there are still far bigger holes in the system to fix first

PS - I agree with your other comments about PP's homebrew silver transformer and other wave shaping mods. I played with that a lot and best result was without. It's like sticking a few valves in the way of the music.

thanks i really appreciate the validation
people think im mad enough as is

its not just ppa but if u signal shape into a sine wave instead of a square wave it has a smoothing effect just like valves
and if you have pre-ringing it sounds edgy or harsh
a cleanish square wave is optimal providing resolution
when you increase resolution you make the system more revealing and quite possibly highlighting further issues in the system
the ppa signal handling is the sugar in the espresso method (which for the most part is suited to mid to low level audio pcs)
my way of thinking is if you dont like your espresso without sugar you need to review your raw materials and brew method

[jkeny]

thanks i really appreciate the validation
people think im mad enough as is

its not just ppa but if u signal shape into a sine wave instead of a square wave it has a smoothing effect just like valves
and if you have pre-ringing it sounds edgy or harsh
a cleanish square wave is optimal providing resolution
when you increase resolution you make the system more revealing and quite possibly highlighting further issues in the system
the ppa signal handling is the sugar in the espresso method (which for the most part is suited to mid to low level audio pcs)
my way of thinking is if you dont like your espresso without sugar you need to review your raw materials and brew method

Jaysus, when did the barista training school open up on TnHF? :)

I agree, Nige, what yu want is a fast signal without ringing - as you say the PPA stuff is creating a slower wave & as a result changing a square wave into a Sine wave which, on the one hand could reduce ringing if it was present but on the other will likely introduce timing issues i.e jitter - how all this pans out in the final audibility would probably be system-dependent

[nige2000]

thanks i really appreciate the validation
people think im mad enough as is

its not just ppa but if u signal shape into a sine wave instead of a square wave it has a smoothing effect just like valves
and if you have pre-ringing it sounds edgy or harsh
a cleanish square wave is optimal providing resolution
when you increase resolution you make the system more revealing and quite possibly highlighting further issues in the system
the ppa signal handling is the sugar in the espresso method (which for the most part is suited to mid to low level audio pcs)
my way of thinking is if you dont like your espresso without sugar you need to review your raw materials and brew method

Jaysus, when did the barista training school open up on TnHF? :)

I agree, Nige, what yu want is a fast signal without ringing - as you say the PPA stuff is creating a slower wave & as a result changing a square wave into a Sine wave which, on the one hand could reduce ringing if it was present but on the other will likely introduce timing issues i.e jitter - how all this pans out in the final audibility would probably be system-dependent

I could do with some barista training myself
I still make the odd bad one

Really only an observation
Besides the usual better resolution and clarity better clocks and power supplies bring
No matter which clock or where in the system pc or in dac if the clock signal edges become rounded there is a smoothing effect to the sound
And on clean edges resolution improves
With ringing its just harsh and unpleasant
i dont often see ringing with batteries

[jkeny]

I could do with some barista training myself
I still make the odd bad one

There's a good barista training school on a road between Grafton St. & Dawson St. - they serve nice coffee too - I'm sure some of the coffee aficionados here know of it & have an opinion?

Really only an observation
Besides the usual better resolution and clarity better clocks and power supplies bring
No matter which clock or where in the system pc or in dac if the clock signal edges become rounded there is a smoothing effect to the sound
And on clean edges resolution improves
With ringing its just harsh and unpleasant
i dont often see ringing with batteries

Yea, I agree & an interesting observation about batteries & ringing - ringing is usually considered the initial, momentary overshoot of the signal (especially fast signals) above where it should be before it settles back to it's correct level - I never consider the implications of PS on this ringing before, which was stupid of me, really - something to think about

[Octagon]

if you dont like your espresso without sugar you need to review your raw materials and brew method

:)
Nige, lovely picture - couldn't agree more

Cheers
Thomas