Re: Finished My-Ref Rev C
George, the most important things first, it is good to know you are OK, and that you managed to have some fun while the storm was blowing. 🙂
I would tend to agree with your subjective review. I like REV C a lot.
Cheers!
Russ
George, the most important things first, it is good to know you are OK, and that you managed to have some fun while the storm was blowing. 🙂
I would tend to agree with your subjective review. I like REV C a lot.
Cheers!
Russ
Re: Finished My-Ref Rev C
Anyone using Windows XP there is a free ultility to resize pictures.
http://www.microsoft.com/windowsxp/using/digitalphotography/learnmore/tips/eschelman2.mspx
Panelhead said:
Anyone using Windows XP there is a free ultility to resize pictures.
http://www.microsoft.com/windowsxp/using/digitalphotography/learnmore/tips/eschelman2.mspx
Re: Re: Finished My-Ref Rev C
Actually, if you're on XP, Google makes a great image organising and processing tool, working in the same manner as iPhoto on the Macintosh. Like most things google, it's very effective, and it's free to boot!
http://picasa.google.com/index.html
Michael
rabstg said:
Actually, if you're on XP, Google makes a great image organising and processing tool, working in the same manner as iPhoto on the Macintosh. Like most things google, it's very effective, and it's free to boot!
http://picasa.google.com/index.html
Michael
Which is the NFB?
Hi.
About to go to bed, it's late here...
On Russ's beta board, is the NFB = C14?
Got one board complete!
Regards,
Michael
Hi.
About to go to bed, it's late here...
On Russ's beta board, is the NFB = C14?
Got one board complete!
Regards,
Michael
Hi Michael,
The cap in the feedback loop is C9.
C14 is for the speaker protection circuit. 🙂
Glad you are making good progress.
Cheers!
Russ
The cap in the feedback loop is C9.
C14 is for the speaker protection circuit. 🙂
Glad you are making good progress.
Cheers!
Russ
Michael, it you have a couple of them, put a 100nf film cap between the pins of C9 on the bottom of each board. 🙂 You will be glad you did. 😀
Cheers!
Russ
Cheers!
Russ
Picassa is great but...
so is this
http://www.xnview.com/
I prefer it for resizing
It's free
Runs on 98 and upwards
Deals with networks OK.
worth a look.....🙂
mike
so is this
http://www.xnview.com/
I prefer it for resizing
It's free
Runs on 98 and upwards
Deals with networks OK.
worth a look.....🙂
mike
Russ White said:
Yes I do, and I will. They came in the beta parts kit, (thanks Brian), marked C21.
I won't tell you that I spent 5 minutes poring over the board looking for 'C21'... The answer was in this thread 🙂
Time for bed!
Thanks,
Michael
Bypass and mechanical resistance 🙂
Hi Russ!
in my humble opinion, and only for contribution
The bypass of NFB caps it isn't so simply and not always with great results.
It is very important the quality of the bypass cap, and dependfs from the bypassed big cap....
probably, if you use the right "big" cap 220uF 50V Low esr, it's possible that bypass is unnecessary.
For example: if the big cap its a Nichicon low ESR (c9-C24) from Brian (great BOM, Brian!!, sincerely) you could prefer a unique solution, with lower ESR: try Panasonic FC 220uF 50V.
There is a little difference, but the FC it's a little bit better.
For the bypass, the little film cap must be very very fast, and clean!
So you could use Vishay MKT 1872 series 1%, high slope DV/DT, or a little Evox Rifa MKP...great quality, in little box...or Arcontronics R82..
or a panasonic sere E (from Brian Bom the type of 1 uf value)
For Panehead:great with italian gold stereo PCB... but...don't you think that the male faston could be better than yours in "PL" positions?
Mechanical resistance it's important, i mean, and the secondary wires of transformer are about 2 mm diameter.
And so, the ground connection must be greater, for a good sounding and functioning... and so the power connection, and speaker wires...i mean less impedance etc etc...
Ciao
RR
Hi Russ!
in my humble opinion, and only for contribution
The bypass of NFB caps it isn't so simply and not always with great results.
It is very important the quality of the bypass cap, and dependfs from the bypassed big cap....
probably, if you use the right "big" cap 220uF 50V Low esr, it's possible that bypass is unnecessary.
For example: if the big cap its a Nichicon low ESR (c9-C24) from Brian (great BOM, Brian!!, sincerely) you could prefer a unique solution, with lower ESR: try Panasonic FC 220uF 50V.
There is a little difference, but the FC it's a little bit better.
For the bypass, the little film cap must be very very fast, and clean!
So you could use Vishay MKT 1872 series 1%, high slope DV/DT, or a little Evox Rifa MKP...great quality, in little box...or Arcontronics R82..
or a panasonic sere E (from Brian Bom the type of 1 uf value)
For Panehead:great with italian gold stereo PCB... but...don't you think that the male faston could be better than yours in "PL" positions?
Mechanical resistance it's important, i mean, and the secondary wires of transformer are about 2 mm diameter.
And so, the ground connection must be greater, for a good sounding and functioning... and so the power connection, and speaker wires...i mean less impedance etc etc...
Ciao
RR
maf_au said:
Ah yes Riccardo, not just any cap will do, but the ones that michael had in the past, and the 100nf caps which Brian sent should provide good results. BTW Brian also sent Panasonic FC 220uf which do work very well. 🙂
Cheers!
Rus
Cheers!
Rus
Russ White said:
Russ, sincerely, today, i always use the Nichicon of Brian's choice.
They sound right, and are very very good.
I tryed the bypass, too, with good ones, but i think the sound lost a little bit.
So i did cut away the bypass.
Analizing the datasheet, i note that FC caps are a good choice and good enough to eliminate the necessity of Bypass. Thats all.
Piergiorgio Lovati sayd me that a possibility could be use a Solid alluminium cap, for c9 and c24 but the costs are a little big high...
Ciao
Riccardo
faston pins
For Panehead:great with italian gold stereo PCB... but...don't you think that the male faston could be better than yours in "PL" positions?
Mechanical resistance it's important, i mean, and the secondary wires of transformer are about 2 mm diameter.
And so, the ground connection must be greater, for a good sounding and functioning... and so the power connection, and speaker wires...i mean less impedance etc etc...
Ciao
RR
[/B][/QUOTE]
You are right on this. Mine are wirewrap pins, solid square shank. Gotta think they are close to zero ohm resistance.
It most likely works in mine due to power draw. It is seldom runs at over 1 watt output, in fact has never played that loud at home. If it was used to drive normal efficiency speakers I most likely would used heavier wiring and posts.
I used 20 ga wire for the speaker wire connections. It is smaller than the diameter of those pins. The wire in the voice coils of my drivers look to be about 35 ga. The speaker wire connects directly.
Need to learn how to use all this fancy software to shrink my pics to a postable size. Installed in my cramped box, it answers a couple of your queries. The ground is doubled up, two wires, used four pin Neutrik Speakon connectors. And about 8 inches of star quad 16 ga cable to connect from power supply to amp, same is used to connect from connector to board, but about 3 inches there.
Agree completely on the feedback cap, used a 0.33 ufd stacked film and foil to bypass a 220 ufd Rubycon ZL. It was added after pics. Connects from input of electyro to the 390 ohm resistor to get around trace inductance. Gotta go back and do the same to my Rev A board. Suspect it helps.
My amps only has a half day of playing, but it seems to be what I have been looking for.
Thanks again Mauro, Russ, and Piergiorgio for the help.
George
For Panehead:great with italian gold stereo PCB... but...don't you think that the male faston could be better than yours in "PL" positions?
Mechanical resistance it's important, i mean, and the secondary wires of transformer are about 2 mm diameter.
And so, the ground connection must be greater, for a good sounding and functioning... and so the power connection, and speaker wires...i mean less impedance etc etc...
Ciao
RR
[/B][/QUOTE]
You are right on this. Mine are wirewrap pins, solid square shank. Gotta think they are close to zero ohm resistance.
It most likely works in mine due to power draw. It is seldom runs at over 1 watt output, in fact has never played that loud at home. If it was used to drive normal efficiency speakers I most likely would used heavier wiring and posts.
I used 20 ga wire for the speaker wire connections. It is smaller than the diameter of those pins. The wire in the voice coils of my drivers look to be about 35 ga. The speaker wire connects directly.
Need to learn how to use all this fancy software to shrink my pics to a postable size. Installed in my cramped box, it answers a couple of your queries. The ground is doubled up, two wires, used four pin Neutrik Speakon connectors. And about 8 inches of star quad 16 ga cable to connect from power supply to amp, same is used to connect from connector to board, but about 3 inches there.
Agree completely on the feedback cap, used a 0.33 ufd stacked film and foil to bypass a 220 ufd Rubycon ZL. It was added after pics. Connects from input of electyro to the 390 ohm resistor to get around trace inductance. Gotta go back and do the same to my Rev A board. Suspect it helps.
My amps only has a half day of playing, but it seems to be what I have been looking for.
Thanks again Mauro, Russ, and Piergiorgio for the help.
George
Re: faston pins
Hi George
I have High efficency speaker (100 dB i mean)too but i think that' the best important thing in a music message it's the transient, or Peak.
Music it isn't "flat", you know. So the energy output its variable in a single uS..
My Ref it's what i looking for too.Definitively, stop valve...
I'm interesting about 390 ohmm etc. I'll waiting for your photo.
Ciao
🙂
R. Romagnoli
http://213.156.45.208/My_Ref/
[/B][/QUOTE]
You are right on this. Mine are wirewrap pins, solid square shank. Gotta think they are close to zero ohm resistance.
It most likely works in mine due to power draw. It is seldom runs at over 1 watt output, in fact has never played that loud at home. If it was used to drive normal efficiency speakers I most likely would used heavier wiring and posts.
I used 20 ga wire for the speaker wire connections. It is smaller than the diameter of those pins. The wire in the voice coils of my drivers look to be about 35 ga. The speaker wire connects directly.
Need to learn how to use all this fancy software to shrink my pics to a postable size. Installed in my cramped box, it answers a couple of your queries. The ground is doubled up, two wires, used four pin Neutrik Speakon connectors. And about 8 inches of star quad 16 ga cable to connect from power supply to amp, same is used to connect from connector to board, but about 3 inches there.
Agree completely on the feedback cap, used a 0.33 ufd stacked film and foil to bypass a 220 ufd Rubycon ZL. It was added after pics. Connects from input of electyro to the 390 ohm resistor to get around trace inductance. Gotta go back and do the same to my Rev A board. Suspect it helps.
My amps only has a half day of playing, but it seems to be what I have been looking for.
Thanks again Mauro, Russ, and Piergiorgio for the help.
George [/B][/QUOTE]
Hi George
I have High efficency speaker (100 dB i mean)too but i think that' the best important thing in a music message it's the transient, or Peak.
Music it isn't "flat", you know. So the energy output its variable in a single uS..
My Ref it's what i looking for too.Definitively, stop valve...
I'm interesting about 390 ohmm etc. I'll waiting for your photo.
Ciao
🙂
R. Romagnoli
http://213.156.45.208/My_Ref/
[/B][/QUOTE]
You are right on this. Mine are wirewrap pins, solid square shank. Gotta think they are close to zero ohm resistance.
It most likely works in mine due to power draw. It is seldom runs at over 1 watt output, in fact has never played that loud at home. If it was used to drive normal efficiency speakers I most likely would used heavier wiring and posts.
I used 20 ga wire for the speaker wire connections. It is smaller than the diameter of those pins. The wire in the voice coils of my drivers look to be about 35 ga. The speaker wire connects directly.
Need to learn how to use all this fancy software to shrink my pics to a postable size. Installed in my cramped box, it answers a couple of your queries. The ground is doubled up, two wires, used four pin Neutrik Speakon connectors. And about 8 inches of star quad 16 ga cable to connect from power supply to amp, same is used to connect from connector to board, but about 3 inches there.
Agree completely on the feedback cap, used a 0.33 ufd stacked film and foil to bypass a 220 ufd Rubycon ZL. It was added after pics. Connects from input of electyro to the 390 ohm resistor to get around trace inductance. Gotta go back and do the same to my Rev A board. Suspect it helps.
My amps only has a half day of playing, but it seems to be what I have been looking for.
Thanks again Mauro, Russ, and Piergiorgio for the help.
George [/B][/QUOTE]
email
Ricardo,
Shot me an email. I used an elcheapo nonmagnetic metal film this time for the 390 ohm resistor. Used an AB carbon comp on first two. I have access to much better quality locally, just have not tried them here. This discussion may be better offline.
Since it is series with the electrolytic, the 390 ohm did not seem to be very critical. Maybe.
All three of the Italian posters do not list an email address. Is there a worry about spam from listings?
George
Ricardo,
Shot me an email. I used an elcheapo nonmagnetic metal film this time for the 390 ohm resistor. Used an AB carbon comp on first two. I have access to much better quality locally, just have not tried them here. This discussion may be better offline.
Since it is series with the electrolytic, the 390 ohm did not seem to be very critical. Maybe.
All three of the Italian posters do not list an email address. Is there a worry about spam from listings?
George