This one's supposed to be pretty good:
To be found on www.triodedick.com (Dutch only -check 'projects')
To be found on www.triodedick.com (Dutch only -check 'projects')
Shoog said:
I think I found it
http://www.diyaudio.com/forums/showthread.php?postid=335624
Here
This is the schematic
is this the illustrious "El Cheapo phono stage"?
alexmoose said:
It's the valve El Cheapo, there is an opamp El Cheapo version.
I've built the valve El Cheapo and am well pleased with it. There is another thread started by Kofi Anan with a lot of detail on the build particularly the earthing. I found that I needed to build the psu separate from the stage as there was too much noise, but I am using a v.low output cartridge.
Kev
Okay, I have identified the "El cheapo" (whoever dubded it that needs a metal) However being a nube to tubes, I of course have some questions that will make me look like an idiot.
What does the number mean after the resistor value in some of the resitors for example 51k1 (bottom left corner) does this imply 1 watt? resistor with a value of 51k ohms?
How much current do you think this needs? because the Hammond 269 JX provides 250v (the B+ on the schem) at 60ma for a modest $33.95 from Tubes and more is this enough?
What does the capacitor labeled "2u(mew)2" (middle right) mean? I understand way by which capacitors are rated, but what does that mean?
What does "MKP" mean?
What does "KP-SN" mean?
What does the number mean after the resistor value in some of the resitors for example 51k1 (bottom left corner) does this imply 1 watt? resistor with a value of 51k ohms?
How much current do you think this needs? because the Hammond 269 JX provides 250v (the B+ on the schem) at 60ma for a modest $33.95 from Tubes and more is this enough?
What does the capacitor labeled "2u(mew)2" (middle right) mean? I understand way by which capacitors are rated, but what does that mean?
What does "MKP" mean?
What does "KP-SN" mean?
alexmoose said:
Hi Alex,
51k1 = 51.1K resistor
2u2 = 2.2uF capacitor
MKP is a type of film capacitor, Polypropelene, like Vishay, Epcos, or the more exotic ones.
KP-SN is a type of film capacitor, Tin Foil, like Audyn-Cap
I'm posting the PSU that KYW suggests, below
I'm going to use the cheap Illinois Caps for mine, except for the 2.2uF (2u2) in which I'll use Mundorf Supreme (because they're relatively cheap here in the Philippines). Farnell and RS Components pricing here is unbelievable, more expensive than botique parts such as Jensen, AuriCap, MultiCap.
Attachments
??What does the number mean after the resistor value in some of the resitors for example 51k1 (bottom left corner) does this imply 1 watt? resistor with a value of 51k ohms???
51.1 k (put the decimal point in the place of the order of magnitude signifier). The history behind this practice is that, back in the days before digital copying was the norm, decimal points often disappeared from a photocopy, but letters usually didn't.
??How much current do you think this needs? because the Hammond 269 JX provides 250v (the B+ on the schem) at 60ma for a modest $33.95 from Tubes and more is this enough? ??
60 mA is plenty for this phono preamp: each triode section would draw in the single digits of mA, the whole thing should draw less than 25 mA from the B+ rail.
??What does the capacitor labeled "2u(mew)2" (middle right) mean? I understand way by which capacitors are rated, but what does that mean???
2.2 uF (2.2 microFarads).
??What does "MKP" mean? What does "KP-SN" mean? ??
These are designators for capacitor types, MKP = metallized polypropylene film, KP-SN = polypropylene and tin foil.
51.1 k (put the decimal point in the place of the order of magnitude signifier). The history behind this practice is that, back in the days before digital copying was the norm, decimal points often disappeared from a photocopy, but letters usually didn't.
??How much current do you think this needs? because the Hammond 269 JX provides 250v (the B+ on the schem) at 60ma for a modest $33.95 from Tubes and more is this enough? ??
60 mA is plenty for this phono preamp: each triode section would draw in the single digits of mA, the whole thing should draw less than 25 mA from the B+ rail.
??What does the capacitor labeled "2u(mew)2" (middle right) mean? I understand way by which capacitors are rated, but what does that mean???
2.2 uF (2.2 microFarads).
??What does "MKP" mean? What does "KP-SN" mean? ??
These are designators for capacitor types, MKP = metallized polypropylene film, KP-SN = polypropylene and tin foil.
By the way Alex, not to confuse you but, I found the suggested rectifier, the 6X4 noisy on my 12B4 preamp. I replaced it with 5Y3 and it's silent. However, I don't like the huge voltage drop with the 5Y3.
Recently, I've had very good successes with solid state
(i know, i know) recitification on my preamps. They are silent, way cooler, smaller (i like nice, small chassis). I'm planning to use the attached schema which I pulled out from HeadWize. Just ignore the relay stuff...
EDIT: Sorry, haven't had morning coffee yet. The suggested rectifier is EZ80 and *not* 6X4 as I posted.
Recently, I've had very good successes with solid state
(i know, i know) recitification on my preamps. They are silent, way cooler, smaller (i like nice, small chassis). I'm planning to use the attached schema which I pulled out from HeadWize. Just ignore the relay stuff...EDIT: Sorry, haven't had morning coffee yet. The suggested rectifier is EZ80 and *not* 6X4 as I posted.
Attachments
alexmoose said:
Hi Alex,
that's the simulation result from the PSU Designer II software, which most of use use to prototype power supplies.
It shows the voltages along each stage of the power supply. If you have the software, you can check the "ripple" (noise) by zooming in on one of the lines.
I have no inhabition toward using a SS recitfier, it just seems a little more practical. Is there any real advantage using a tube rectifier? other than the fact that alot of them look really cool?
Arnoldc, could you explain the data thats in the attatchment from the previous post? the graph, showing the suggested power supply, I am very close to understanding it, however I am not sure, please enlighten me
Arnoldc, could you explain the data thats in the attatchment from the previous post? the graph, showing the suggested power supply, I am very close to understanding it, however I am not sure, please enlighten me
The numeric results on the left pane shows the simulated voltages at each stage - "Max" column.
I really like this software so much, and the simulated values are always close to the real world values. I use it in all my projects, whether SS or tube rectification.
EDIT:
he he, you're fast...
Changing the capacitance does not change the voltage but will have an effect on the ripple. If you want to play around with the resulting voltage, you can change the R.
Another EDIT:
The 10uF first capacitor is sized according to the maximum capacitance limit of the tube rectifier, the EZ80 in this case. Each tube rectifier will have a different capacitance limit for a cap-input supply, like this.
I ditched, the EZ80 and 10uF, replaced it with FR107 and power transformer is 280V I think, in one of my projects.
I really like this software so much, and the simulated values are always close to the real world values. I use it in all my projects, whether SS or tube rectification.
EDIT:
he he, you're fast...
Changing the capacitance does not change the voltage but will have an effect on the ripple. If you want to play around with the resulting voltage, you can change the R.
Another EDIT:
The 10uF first capacitor is sized according to the maximum capacitance limit of the tube rectifier, the EZ80 in this case. Each tube rectifier will have a different capacitance limit for a cap-input supply, like this.
I ditched, the EZ80 and 10uF, replaced it with FR107 and power transformer is 280V I think, in one of my projects.
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.