input impedance and sensitivity
Hi Nordic,
sorry that I have to post this in here... cause the original thread from Carlos has been very long... and I believe he is busy working on the next generation DX...
do you know what is the input impedance of the HDII version?
this is important for me since I need to calculate line level notch filter that I like to experiment with...
also, what is the input sensitivity of this amp? (or gain actually? with recommended power supply voltage?)
I wonder if using simple passive preamp just a pot like my gainclone would work... (my gainclone with +/- 25VDC PSU has pretty sensitive input at 0.6Volt so I can easily use just a pot for passive "preamp")
Regards,
---
David
Hi Nordic,
sorry that I have to post this in here... cause the original thread from Carlos has been very long... and I believe he is busy working on the next generation DX...
do you know what is the input impedance of the HDII version?
this is important for me since I need to calculate line level notch filter that I like to experiment with...
also, what is the input sensitivity of this amp? (or gain actually? with recommended power supply voltage?)
I wonder if using simple passive preamp just a pot like my gainclone would work... (my gainclone with +/- 25VDC PSU has pretty sensitive input at 0.6Volt so I can easily use just a pot for passive "preamp")
Regards,
---
David
Unfortunately my meter goes only to 2Meg ohm... not enough to measure for you... just post in the DX thread, Carlos checks it, and will gladly provide the info.
The board factory just phoned, they would have been done allready, but apparently the board v-scoreing machine got stuck... guess they are not dealing with such big orders every day.
They said I can collect tommorrow morning.
I am now going to send off PSU boards to the fab, I redesigned the PCB to take 35mm caps as I would later, when finances allows for it, like to install Sikorel caps there... will just have to manualy drill holes for the 13mm nuts on those. In the meantime it accepts standard 10mm snap in caps. Low ESR units are commonly available in 35mm.
I expect the price to be about the same as the amp boards, allthough it may differ a little due to the smaller order.
I will request qoutes on 1 and 2 oz, but I think 1 oz is more than enough considering trace widths.
I guess going on past experience, these won't be ready before Tuesday.
Let me know if you are interested, and want to keep your order so both orders can ship together.
As always, a PSU is not a cheap item. this is my first amp I feel deserves some good caps (>$10 each) (my prototype is working happily on $2 caps in the meantime).
The board factory just phoned, they would have been done allready, but apparently the board v-scoreing machine got stuck... guess they are not dealing with such big orders every day.
They said I can collect tommorrow morning.
I am now going to send off PSU boards to the fab, I redesigned the PCB to take 35mm caps as I would later, when finances allows for it, like to install Sikorel caps there... will just have to manualy drill holes for the 13mm nuts on those. In the meantime it accepts standard 10mm snap in caps. Low ESR units are commonly available in 35mm.
I expect the price to be about the same as the amp boards, allthough it may differ a little due to the smaller order.
I will request qoutes on 1 and 2 oz, but I think 1 oz is more than enough considering trace widths.
I guess going on past experience, these won't be ready before Tuesday.
Let me know if you are interested, and want to keep your order so both orders can ship together.
As always, a PSU is not a cheap item. this is my first amp I feel deserves some good caps (>$10 each) (my prototype is working happily on $2 caps in the meantime).
Attachments
Gotcha, what does it do?
I got the boards today, I was a little unhappy, as they only put soldermask on the bottom, and used the guillotine when the v-score machine broke (apparently it is fixed again now).
Luckily they cut the boards larger than the corner marks, so a little fileing should make em look tip top again. I am happy with the silkscreen, and the soldermask is 98% ok, probably equal to normal commercial grade. Do scrape away some mask on small pads, if you are scared you can not get the solder in.... one pad that caught my eye was on D1. Some of them are just fine though.
If you don't own flux, go buy some... it will help your soldering 500%.
I got the boards today, I was a little unhappy, as they only put soldermask on the bottom, and used the guillotine when the v-score machine broke (apparently it is fixed again now).
Luckily they cut the boards larger than the corner marks, so a little fileing should make em look tip top again. I am happy with the silkscreen, and the soldermask is 98% ok, probably equal to normal commercial grade. Do scrape away some mask on small pads, if you are scared you can not get the solder in.... one pad that caught my eye was on D1. Some of them are just fine though.
If you don't own flux, go buy some... it will help your soldering 500%.
Attachments
Hi Nordic,
Congradulations !!
When components are located on copper planes it prevents the heat from the soldering iron escaping into the large copper surface.
Soldermasks only go on the side with the traces and solder. On a single sided board that's on the bottom side of the PCB.
I always sand my PCB edges. I use a piece of fine sandpaper on a flat surface and sand until the colour of the edge matches the PCB surface colour.
Do you use rosin cored solder? I've never needed extra flux on soldering PCBs. I do clean the PCB with alcohol before soldering to ensure all traces of oil are removed.
BTW: I've soldered a lot of different metals over the years with lots of different fluxes.
regards
Congradulations !!
Nordic said:
When components are located on copper planes it prevents the heat from the soldering iron escaping into the large copper surface.
Nordic said:
Soldermasks only go on the side with the traces and solder. On a single sided board that's on the bottom side of the PCB.
Nordic said:
I always sand my PCB edges. I use a piece of fine sandpaper on a flat surface and sand until the colour of the edge matches the PCB surface colour.
Nordic said:
Do you use rosin cored solder? I've never needed extra flux on soldering PCBs. I do clean the PCB with alcohol before soldering to ensure all traces of oil are removed.
BTW: I've soldered a lot of different metals over the years with lots of different fluxes.
regards
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