Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: kagliostro on March 29, 2013, 09:01:30 am

Title: Are ecc85 - pcf802 - pcc189 - ec88 tubes usable in audio amp ??
Post by: kagliostro on March 29, 2013, 09:01:30 am

Are this tubes usable for our guitar amps ?

ecc85 - pcl802 pcf802 - pcc189 - ec88

http://www.nj7p.info/Common/Tube/SQL/Tube_query.php?Type=ECC85 (http://www.nj7p.info/Common/Tube/SQL/Tube_query.php?Type=ECC85)
http://www.nj7p.info/Common/Tube/SQL/Tube_query.php?Type=6AQ8 (http://www.nj7p.info/Common/Tube/SQL/Tube_query.php?Type=6AQ8)

http://www.r-type.org/pdfs/pcf802.pdf (http://www.r-type.org/pdfs/pcf802.pdf)

http://www.r-type.org/pdfs/pcc189.pdf (http://www.r-type.org/pdfs/pcc189.pdf)

http://www.mif.pg.gda.pl/homepages/frank/short/001/e/EC88.gif (http://www.mif.pg.gda.pl/homepages/frank/short/001/e/EC88.gif)
http://www.nj7p.info/Common/Tube/SQL/Tube_query.php?Type=EC88 (http://www.nj7p.info/Common/Tube/SQL/Tube_query.php?Type=EC88)

thanks

K

Title: Re: Are ecc85 - pcf802 - pcc189 - ec88 tubes usable in audio amp ??
Post by: darryl on March 29, 2013, 06:53:06 pm

ECC85 - probably. It's a twin triode, but can't be used as a plug-in replacement for the 12A*7 family because it has a 6.3V heater using pins 4 & 5. The heater current is roughly 50% more than a 12AX7.

PCF802 - possible, but the 9V heater would make it impractical.

PCC189 - another twin triode, but variable mu. Not very useful for audio, and a 7.6V heater.

EC88 - single triode. Possibly usable, but twin triodes are a much more efficient use of chassis space.


Almost all valves can be used for audio ( except oddities like EHT rectifiers ), but sometimes doing so makes no practical sense. The challenge can be fun though.   :icon_biggrin:

Title: Re: Are ecc85 - pcf802 - pcc189 - ec88 tubes usable in audio amp ??
Post by: kagliostro on March 30, 2013, 06:31:30 am

Thanks Darryl

those are not components that I think to use in serious builds

it's only pursuit

K