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Questions for the tubelab SSE build

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Hello, i am kind of new to the DIY but have been lurking on this forum for quite a while now.

Pardon if my english is not correct.

I have bought boards for both SE and SSE amp from tubelab.com
The boards did arrive some weeks ago and all the parts have been dropping in now
to be able to build the Tubelab SSE amplifier =).

The one part i have not order and like to ask about if it is possible: The choke

The parameters for a choke people show on forum that can work is: 10 Henry, 150 - 500 mA, DC Resistance: 100 ohms (i want to buy locally and the one that i have close to me here in europe that i know of is a polish company: Transformatory toroidalne - Producent transformatorow Toroidy.pl

The problem: toroidy.pl dont have this value of DC resistance 100 ohms, they ondly have at its peak 66,5Ω, will that work any way ?


Here is the one that i want to buy if it will work: TDS10/500 - Toroidal Choke 10H 500mA DC - Shop Toroidy.pl

Or is it pointless overkill with the values it has ?


This is the chokes they can offer: Toroidal DC Chokes - Shop Toroidy.pl

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What numbers do the grid leak resistors have on the SSE board ?

I cant find this on Tubelab | Dedicated to advancing the state of the art in affordable high end audio. =( ondly on forum that mension that there is grid leak resistors"


Kind regards SegaTomas // Sweden
 
I was away for almost two weeks with only a phone for internet access. I have been catching up on email and sent you a reply. Here are the details:

The 65 ohm choke should work fine.

The term "grid leak" is an old term that referred to a method of biasing that isn't often used today. It used a very high value resistor in the 1 to 5 megohm range from the grid to ground to create a negative voltage on the grid by slowly "leaking" electrons from the grid to ground. There will always be a path from grid to ground in all tube amps, usually a resistor or something else in the bias circuitry like a transformer or a mosfet. These resistors are sometimes incorrectly called grid leak resistors. The resistors in the output stage are R15 and R25. The resistors in the preamp stage are R11 and R21.

There are also resistors called "stoppers" in the grid circuit. These are low valued resistors to prevent oscillation. They are not present in all amplifiers. The stopper resistors in the SSE are R16 and R26 in the output stage. R12 and R22 are the stopper resistors in the preamp stage.
 
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I have bought boards for both SE and SSE amp from tubelab.com
The boards did arrive some weeks ago and all the parts have been dropping in now to be able to build the Tubelab SSE amplifier.


Hello Thomas,

I intend to build a SSE as well. I'm located in Switzerland and would prefer to order the heavy iron from Poland than from USA... I noted the Toroidy choke. Did you as well buy your PSU and OPT from Toroidy ? And if yes, what models ?

Thanks!
Charles
 
Thank you George for the answer! =)
If it can be interesting i bought transformers before from a company that also makes a alternative / improvement to the grid choke, see link:

SAC Thailand
----

Hallo Charles.
I did import from edcore the output transformer and then took the power transformer from mouser: Hammond 374BX

I think Toroidy have options that will work, just send mail to them! =)

Kind regards SegaTomas // Sweden
 
R12 and R22 are the stopper resistors in the preamp stage. __________________




I thought this was interesting as I thought that the Tubelab SSE was purely an amplifier and that I would need to provide a preamp for my turntable, tuner and cd player.
Confused here.
 
I was under the impression that the SSE was an amplifier only and that I would need to buy a preAmp. The comment that I quoted says that the SSE already seems to have a preamp built in.

It really boils down to how much voltage your source can provide. Here's a quote from an old thread:

The amp is designed such that under the worst case (KT88 in triode with CFB) the amp can be driven to clipping with a CD player (about 2 V p-p) In the other extreme (EL 34 in UL without CFB) the sensitivity can be as high at .75 V p-p.

jeff
 
R12 and R22 are the stopper resistors in the preamp stage.

Technically I should have said "driver stage."

I was under the impression that the SSE was an amplifier only and that I would need to buy a preAmp.

Most builders simply connect their SSE directly up to a CD player, DAC, PC soundcard, or other line level output and everything works fine. Some builders drive the SSE from a phone, iPAD or iPOD. In this case the portable device may not be able to drive the SSE to hard clipping, but often it is plenty loud unless inefficient speakers are used.

You can not directly connect the output of a modern turntable (magnetic cartridge) to the SSE. For this you will need a dedicated phono stage or an integrated preamp.
 
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