Well, i had a listen to the PS1 the other day. It wasnt bad but not as good as my 'old school' battleship sized technics.
I didnt bother leaving it on for 3 days. Do you just need to leave it plugged in and on at the wall, or actually switched on at the unit?
Anyhow, i just pulled it apart and started playing.
I 'should' have just bypassed the output stage but havent tested it yet so may have only succeeded in ruining it completely. Ill plug it in in a bit and see if it still works. I guess it should work fine but be super quiet.
I already have a 5687 stage built so ill use this as an output stage rather than the pre-amp it was intended to be.
The 5687 stage was rolling off the treble when used with my phono so we'll see what it does now.
Time for a coffee and a cigarette then ill see what happens with it.
Valve output stage for PS1
#2
There were tiny bugs living on the circuit board 
Are they usual?
So, i gave it a thorough cleaning with electronics cleaner, hopefuly thats sorted em out.
This is what i followed to bypass the output stage, but i used 2.2uf instead of 3.3uf, because i couldnt get any 3.3uf.
http://dogbreath.de/PS1/output/output.html
And this is the 5687 stage ill try as an output stage for the PS1.
http://diyparadise.com/preamptutorial.html
Are they usual?
So, i gave it a thorough cleaning with electronics cleaner, hopefuly thats sorted em out.
This is what i followed to bypass the output stage, but i used 2.2uf instead of 3.3uf, because i couldnt get any 3.3uf.
http://dogbreath.de/PS1/output/output.html
And this is the 5687 stage ill try as an output stage for the PS1.
http://diyparadise.com/preamptutorial.html
#3
Pluged it in and tried it.
Works fine, thats odd, no output stage n all that. Its a bit quieter but not alot. I assume the PS1 output stage isnt doing alot then!
Sounds better already. A bit confused maybe, still not amazing, but better.
So, onwards and upwards, plug it through the 5687.
WOW!!!!!
Seriously, this is fantastic! Everything is so well seperated, in its place, controlled and detailed.
Ive never heard my CD's like this, its quite shocking. Ive got the silliest grin on my face, i cant believe it sounds this good!
Got a problem with the power supply though.
Ive got hum, but not normal hum, higher pitched. Sort of like hum mixed with a high pitch sizzle/tingle, a bit like an unearthed turntable.
It goes as soon as i kill the power so its got to be in the PSU right? Or, because of the umbilicle, it could be caused by interferance in the passive pre from the HV line in? I dunno, any ideas?
The rolled off treble hasnt happened, sounds great. Bass is tight and controlled, detail is amazing, placement of instruments/vocals is brill.
I didnt know CD could do this
Works fine, thats odd, no output stage n all that. Its a bit quieter but not alot. I assume the PS1 output stage isnt doing alot then!
Sounds better already. A bit confused maybe, still not amazing, but better.
So, onwards and upwards, plug it through the 5687.
WOW!!!!!
Seriously, this is fantastic! Everything is so well seperated, in its place, controlled and detailed.
Ive never heard my CD's like this, its quite shocking. Ive got the silliest grin on my face, i cant believe it sounds this good!
Got a problem with the power supply though.
Ive got hum, but not normal hum, higher pitched. Sort of like hum mixed with a high pitch sizzle/tingle, a bit like an unearthed turntable.
It goes as soon as i kill the power so its got to be in the PSU right? Or, because of the umbilicle, it could be caused by interferance in the passive pre from the HV line in? I dunno, any ideas?
The rolled off treble hasnt happened, sounds great. Bass is tight and controlled, detail is amazing, placement of instruments/vocals is brill.
I didnt know CD could do this
#4
Oh, the 5687 stage is in my passive pre. Its wired phono plugs, into the 5687 with 1k grid stoppers. The outputs are wired to the selector switch, therefore one input is permenantly through the 5687.
The 5687 will get re-housed soon.
The 5687 will get re-housed soon.
#6
You might find that its picking up assorted digital noise from inside the ps1. It might also be because you have removed any low pass filter on the output stage.
Whenever an honest man discovers that he's mistaken, he will either cease to be mistaken or he will cease to be honest.
#7
Just went to check a few things.
I may help if i earthed the thing
All earthed now and hum has gone, sort of.
If i run the 5687 stage, with no input, i get hum.
Plug the inputs in and the hum goes, i need to check the earths for everything but its not really an issue. I guess the 5687 stage is only earthing properly via the CD player?
All i have now is a 'snowing' kind of hiss which increases with volume. I assume this is just noise within the 5687 stage itself. What causes this, is it just noise created by the 5687 stage that i can do nothing about, or is it picking up intereferance. Is it worth fitting an earthed valve shield?
I may help if i earthed the thing
All earthed now and hum has gone, sort of.
If i run the 5687 stage, with no input, i get hum.
Plug the inputs in and the hum goes, i need to check the earths for everything but its not really an issue. I guess the 5687 stage is only earthing properly via the CD player?
All i have now is a 'snowing' kind of hiss which increases with volume. I assume this is just noise within the 5687 stage itself. What causes this, is it just noise created by the 5687 stage that i can do nothing about, or is it picking up intereferance. Is it worth fitting an earthed valve shield?
#8
All valves produce noise for a number of reasons. One reason is that any conductor produces noise, the amount being proportional to the resistance of the conductor. So a 1M resistor will produce more of this type of noise than a 1k resistor. Thats fixed, can't be avoided. Valves also produce noise du to the movement of electrons, the stream of electron passes the grid, but a random number of then strike the grid, this also produces noise.
Some valves produce more noise than others, you wiull often see the noise level of the latter produced valves quoted as a equivilant resistance, this is saying the valve produces noise thats equivilant to a resistor of that valve. The gain of the valve will then amplify that noise.
Everything produces noise, but whats important is the signal to noise level. Your pree will pb producing noise, but it the excessive gain means that the signal going in need to be attenuated by 20dB, then the result will have a signal to noise ration thats 20dB worst that is possible,
Noise is a complex subject, feedback will affect noise, but not always in a obvious way, as the noise source is not correlated (simply that means its random). Adding two equal noise sources togethre doesn't produce twice the noise, and so on.
Some valves produce more noise than others, you wiull often see the noise level of the latter produced valves quoted as a equivilant resistance, this is saying the valve produces noise thats equivilant to a resistor of that valve. The gain of the valve will then amplify that noise.
Everything produces noise, but whats important is the signal to noise level. Your pree will pb producing noise, but it the excessive gain means that the signal going in need to be attenuated by 20dB, then the result will have a signal to noise ration thats 20dB worst that is possible,
Noise is a complex subject, feedback will affect noise, but not always in a obvious way, as the noise source is not correlated (simply that means its random). Adding two equal noise sources togethre doesn't produce twice the noise, and so on.
Whenever an honest man discovers that he's mistaken, he will either cease to be mistaken or he will cease to be honest.
#9
So, apart from using components that make less noise there's not much i can do?
The noise doesnt get bad untill its at levels louder than i would listen anyway so its not a huge issue.
This may sound stupid, i may not be understanding this properly, but ...
Signal to noise.
The more gain the pre provides the noisier it will be (super simplified for the sake of argument)
We want to keep as much signal as possible going in and use as little gain as we have to.
Is there anyway to make the 5687 provide less gain and therefore less noise, or is it a case of building a different pre that suits my needs better?
Appologies if im mis-understanding and talking complete rubbish
The noise doesnt get bad untill its at levels louder than i would listen anyway so its not a huge issue.
This may sound stupid, i may not be understanding this properly, but ...
Signal to noise.
The more gain the pre provides the noisier it will be (super simplified for the sake of argument)
We want to keep as much signal as possible going in and use as little gain as we have to.
Is there anyway to make the 5687 provide less gain and therefore less noise, or is it a case of building a different pre that suits my needs better?
Appologies if im mis-understanding and talking complete rubbish
#10
Well, if you reduce the gain, the noise will stay the same, but the signal will in effect be louder, ho higher signal to noise.Is there anyway to make the 5687 provide less gain and therefore less noise, or is it a case of building a different pre that suits my needs better?
You can reduce the gain by removing the cathode cap (as suggested) or by converting to a cathode follower ( gain < 1 ) or you could convert it into a anode follower wixh could produce any gain you want less that the gain you have now. Connecting a resistor from the output (after the coupling cap, to the grid, and inserting another resistor between the input and the grid will make it a aanode follower. The ratio of the two resistors will set the gain.
Whenever an honest man discovers that he's mistaken, he will either cease to be mistaken or he will cease to be honest.
#12
Oh, i just played some tunes to the wife.
She's super diss-interested in all this.
Even she thought it sounded good. She was surprised you can hear the detail of bass notes.
She even went and got one of her CD's to try (smiths )
It must be doing something right if its got her interest!
She's super diss-interested in all this.
Even she thought it sounded good. She was surprised you can hear the detail of bass notes.
She even went and got one of her CD's to try (smiths
)It must be doing something right if its got her interest!
#13
Interesting things these PS1s, aren't they.
Sometimes they have flashes of brilliance that make you sit up and listen harder.
Other times i still get the feeling that something isn't right.
Suppose my next step before building a new power supply, is to hook it up to the Lampizator and see what occurs.
Sometimes they have flashes of brilliance that make you sit up and listen harder.
Other times i still get the feeling that something isn't right.
Suppose my next step before building a new power supply, is to hook it up to the Lampizator and see what occurs.
Much to learn there is.
#14
I dont get that 'not right' feeling anymore 
Just bypassing the output stage is still didnt sound great.
For whatever reason it gets on really well with the valve output stage.
Without the 5687 output stage it would be back in the bottom of the cupboard.
Just bypassing the output stage is still didnt sound great.
For whatever reason it gets on really well with the valve output stage.
Without the 5687 output stage it would be back in the bottom of the cupboard.
#15
Well, i just lashed up the PS1 to the Lampizator, and it seems to work fine.
Now i've just got to remove two teenagers from the living room, so i can do some listening. Thats the tricky bit.
Now i've just got to remove two teenagers from the living room, so i can do some listening. Thats the tricky bit.
Much to learn there is.