I'm looking for 417a/5842 Preamp Schematic without any Transformer, any suggestion ?

[calico88]

does anyone ever built using this tube for Preamp without using any transformer and still get the best sound Quality ?

I've googling the schematic but they are using transformer, all I need is a Simple Schematic with less component use.

any Schematic recommendation ?

cal

 

[phn]

Replace the trafo with a 3 to 5 k resistor. But you will get very high gain.

Better use 12B4, 407A or 5687.

 

[phn]

Sorry for the hasty, incomplete answer.

You need to change B+ to 250V and the transformer replaced with a 4.7k resistor. But, again, you will get a lot of gain. 1 volt in will be 30 volts out. Most power amps have a sensitivity of 500mV or less.

 

[calico88]

phn,
thanks you for the advice.
ok, I have limited space and I need little/less component or I should say very very simple design.

how big the interstage treansformer are we talking here ? how much it cost and where to buy beside ebay ?

can you show me the good Schematic preamp using this tube ?

or can you recommend any other tube better than this but no OT design ?

cal

 

[barossi]

Hi Cal,
i have good experiences with Lundahl LL1660/18mA together with the 5842 tube. Search for "EURIDICE" and you will find a schematic.

Kind Regards

Barossi

 

[calico88]

Barossi,
I can't find the schematic you said.
found the 4 channel, etc.

I'm looking for the preamp 417a/5842 Schematic that doesn't use any Transformer.

thanks
cal

 

[dshortt9]

I finally found the one that I forgot where it was. Should be really good.

http://www.diyparadise.com/mar06/gg.html

 

[bear]

Thorsten Loesch, Steve Bender and Allen Wright have all published on the web very nice preamps using the 417A as the front end tube.

For best results use it as cascode with a JFET for MC carts.

_-_-bear