HELP PLEASE - with preamp design

[soundbadger]

hello, i am trying to design a single ended valve amp for a college project. i have decided on a cathode biased kt88 output stage coupled to a james js-6123hs output transformer. but i am unsure what would be the best preamp method. so all help would be very much apreciated.
i have looked at many designs but i am unsure.
i have looked at mikael's 6n1p based preamp but am not sure

i was thinking about a 12au7 running both parts either in parallel, cascade, cascode or srpp. i have been reading a lot to try and understand the best uses for each but help would be good.

also what sort of voltage swing should i be looking to send in to the kt88 i was thinking about 50v pk-pk. but again this is just based on what i learned in the past 3 weeks.

any help would be very much appreciated,,,,

soundbadger

 

[ErikdeBest]

Hi Soundbadger

If yoy really want to design your own amplifier I recommend some thorough reading of 'valve amplifiers' by Morgan Jones, available at amazon, and of the stuff available at this thread

Good luck, Erik

 

[soundbadger]

already got it and have been reading it ,,

 

[Sheldon]

If you need some gain you could go with with a grounded cathode 5687 or ECC99. If you don't need as much gain, a 12B4 in the same configuration - many examples of that one here if you search.

Sheldon

 

[leadbelly]

Your terminology is throwing people off. By your project description, it sounds like you are not looking to build a preamp but instead to build the driver stage for your KT88's.

already got it and have been reading it ,,

Then read up on where he discusses driver stages. Especially where he discusses trioded 6EJ7 and EF86.

 

[Conta]

also what sort of voltage swing should i be looking to send in to the kt88 i was thinking about 50v pk-pk.

Yes, you need swing about 40-45V. This preamp can drive KT88 directly:
http://audio.ring.lt/pre/pre_en.htm