6N1P Bass DI - Revisited

[Murdock]

At what frequency did you measure the reactance? Remember good old steel lams have inductance which actually increases at low frequencies so it may be OK down to 20Hz.

Cheers

Ian

Sorry, forgot to mention. It was at 20Hz...

 

[CJ]

XL= 10/0.00135=7407 ohms at 20 hz and 10 v

7407/6.28=1180

1180/20= 60 Henries

Z ratio is 2200/200 = 11:1

Voltage Ratio = root 11 = 3.3:1

should work ,

what are the dimensions of the core?

 

[Murdock]

XL= 10/0.00135=7407 ohms at 20 hz and 10 v

7407/6.28=1180

1180/20= 60 Henries

Z ratio is 2200/200 = 11:1

Voltage Ratio = root 11 = 3.3:1

should work ,

what are the dimensions of the core?

About 72mm x 64mm and 28mm stack height.

 

[Spencerleehorton]

Is there a way to get a bit more gain out of this di using the 6N1P?

 

[ruffrecords]

Is there a way to get a bit more gain out of this di using the 6N1P?

If the cathode resistor is not bypassed then bypassing it will increase the gain a bit.

Cheers

Ian

 

[Spencerleehorton]

So bypass the 220R and 470uf cap?

 

[CJ]

Yes on the caps and you can disconnect the pot on the output if you have one, and do away with the two 330 resistors.

Murdock that core is bigger than the one I use so you should be all set. If you want more bass you could crack the I bars off and remove the paper gap but you have to clean the surfaces before reassembly otherwise you end up worse off than if you left it alone.

 

[ruffrecords]

So bypass the 220R and 470uf cap?

If the 470uF is already across the 220R then it is already fully bypassed. No more gain to be had I am afraid.

 

[My3gger]

Yes on the caps and you can disconnect the pot on the output if you have one, and do away with the two 330 resistors.

Murdock that core is bigger than the one I use so you should be all set. If you want more bass you could crack the I bars off and remove the paper gap but you have to clean the surfaces before reassembly otherwise you end up worse off than if you left it alone.

What are the chances of disassembling Cinemag OT lams varnished after the core was stacked? I have one with 50Ni/50Fe lams having shorted primary, the other has butt stacked iron core with the same windings but i prefer 50Ni sound for this project.
Yes, i connected it between anode and ground, protecting psu and fuse

 

[CJ]

Depends on the varnish, might be air dry epoxy which would be tough.

Steel is a lot more tolerant of a little bending, nickel not so much. 50/50 you might have a shot, the first few lams are tough but once you get room for a knife,it gets pretty easy if you keep it hot.

50/50 lams are usually 0.014" thick which is tougher than power XFMR 0.019" non grain lams.

 

[Egor Reshetnikov]

hopefully not a nuclear sunrise because i believe there is a rocket printed on that tube

it is about spacecraft program in 1960s. There even were children toys named after spacecrafts

 

[soapfoot]

Does this seem like a decent PT candidate for this project?

https://edcorusa.com/collections/tube-power-transformers/products/xpwr083a-200v-40ma-8v-1-5a

 

[djn111]

Hello,

Received two output transfomers from CJ today, I can only say WAUW ! I am very happy with them.

Hope they sound as good as they look

Thanx CJ to make this happen.

DJN

 

[Spencerleehorton]

Does this seem like a decent PT candidate for this project?

https://edcorusa.com/collections/tube-power-transformers/products/xpwr083a-200v-40ma-8v-1-5a

i would stick with toroidal, as this made the biggest difference in noise to my build

 

[Spencerleehorton]

ive just done a shoot out with the noble clone and the REDDI clone and both sound fantastic but for my money i use the REDDI clone with my active preamp bass and the Noble with the passive (but active pickups)

 

[eltnet]

Hello, very nice project.
I would like to buy an xfmr from CJ for this built.
As new members to this forum it seems I can't contact him.
CJ, if you read me maybe you can contact me. Cheers.

 

[CJ]

Shipping is the same price as the transformer, (80 US)

I can send you one but you can cut your shipping cost in half if you can find somebody to do a group buy,

cj

 

[eltnet]

Shipping is the same price as the transformer, (80 US)

Thx for answer. Yep you're right about shipping cost. I don't know if other members are based in Japan. I'll come black to you asap. Thx a lot.

 

[MicDaddy]

Thx for answer. Yep you're right about shipping cost. I don't know if other members are based in Japan. I'll come black to you asap. Thx a lot.

Buy many and become distributor *not financial advice*

 

[eltnet]

Buy many and become distributor *not financial advice*

Haha yes indeed. But unfortunately I have no time for this.