APP Studio Ing's products - APP992 - APP14GE Germanium DOA and other kits

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I would like to close the group buy at 50 pcs or after 10 days.

since these boards need to be powered I offer at only 5 euros one PSU2 board for each two IO pulteq boards bought, this is special price I do to the diy prodigy members.

Pier Paolo
 
hi pier

im interested in the Ge DOA's, do u still have any stock?

would these be a straight swap on a 312 circuit and would they be ok on +/-18V??

cheers
mick

 
0dbfs said:
Hi Pier, Does your pultec board do one or two channels ?

Thanks man!
-jonathan

one channel only

thanks
kind regards
Pier Paolo
 
leadbreath said:
hi pier

im interested in the Ge DOA's, do u still have any stock?

would these be a straight swap on a 312 circuit and would they be ok on +/-18V??

cheers
mick

no, because in these days I have had several orders for this one,
however I am going to start the SMD version (except for the germanium transistors that are PH) so I will have a big stock of them (we speak of working 20 days of time lead). The SMD version is upgraded so it is better sounding.
The SMD resistors in the signal path are panasonic metal film type (top level and expensive).    

the 2050 germanium version is rated for +-16V of power supply

kind regards
Pier Paolo



   


 
It would be really nice to get some more info on these IO boards.
Here, http://www.groupdiy.com/index.php?topic=43859.120
I can see the board, but its hard to find out how it works and which connections are needed.
If you cant put up a schematic, how is about a block diagram?
Where is the board manufactured? China or Italy?
Estimated delivery date would also be helpful...
Thanks for your effort in making these board :)
 
Ptownkid said:
I have not had the time to follow this too closely...do we need these to compliment ruffrecords pcbs?

Ruffrecords has designed the passive eq net, this net needs an input and an output stage to compliment ruffrecords pcbs.

Moreover, Ruffrecords has designed a tube out stage for his passive eq net too.
Using this tube stage and a line trasformer as input stage it is possible to have a complete inductorless pulteq eq1a

But the Ruffrecords' out stage is based on tubes, who wants a solid state input and out stage to compliment ruffrecords pcbs
can be use this my IO board, if he want.  


 
Andreas Pfeiffer said:
It would be really nice to get some more info on these IO boards.
Here, http://www.groupdiy.com/index.php?topic=43859.120
I can see the board, but its hard to find out how it works and which connections are needed.
If you cant put up a schematic, how is about a block diagram?
Where is the board manufactured? China or Italy?
Estimated delivery date would also be helpful...
Thanks for your effort in making these board :)

yes , I am going to put up the shematic tomorrow.

the connections are:

input stage (gain= 0.5 or 1 , 24 dbu)
- balanced line input with 20K of input impedance, that 's the line input of the gear.
- sbalanced out to connect to the passive eq net's input (ruffrecords' eq boards)

fet buffer stage (gain = 1,  12 dbu, note that the passive eq stage attenuates a lot the signal)
- sbalanced 2.2M input from out of ruffrecords eq boards
- sbalanced out

makeup gain stage and out stage (20-36 db of gain max, 24dbu - 32 dbu out,  depending by configuration used)
- sbalanced input 47k of impedance, the signal cames from buffer stage out
- balanced trasformerless out 
- balanced out with trasformer (several trasformers can be used in)
- connector for potentiometer for make up (25k rev log or 10k rev log)

connector for power supply , dual voltage

tomorrrow other infos, now I am going to bed





 
this is the schematic, soon the other docs
 

Attachments

  • IO board for pulteq eq1A.pdf
    283.8 KB
this is the image

IO%20pulteq%20eq%20board%202%20APP.bmp
 

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