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Basic questions on configuring Tube AMP

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Well 3v is ~10% . I need to recheck it in different times of the day to see whether this is the cause for the decrease in voltage . Anyway , I am using 6l6gc tubes and the measuremens were taken without the tubes .
Regarding the max volume , Is it possible that the POT is not covering the full scale of the available volume ?
 
Is it possible that the POT is not covering the full scale of the available volume ?

Not really, here's why:

The pot is a passive device, and it can only subtract (attenuate) the signal. When the pot is turned fully clockwise, it is essentially a short circuit, ie no attenuation/subtraction.

If you measure the pot wiper to the end terminals with the wiper at full travel clockwise, you will get zero ohms (or very close to it) from the wiper to one end, and the value of the pot in ohms from the wiper to the other end. Turn the pot fully CCW, and measure again; you will reverse the above. The pot needs to be out of the circuit to measure the various R's.

So, in summary, with the pot fully clockwise it's like no pot at all, ie zero attenuation. That's as loud as your amp is going to get for a given input signal. Keep in mind that different sources have different output levels as well, ie your ipod may play louder than your CD player, etc.
 
Can the Sansui be run as a power amp?

Hi.
Another interesting question, can I use the Simple SE as preamp (in a certain configuration)?
I just got a nice vintage Sansui AU717 and I dont know how to handle more than one amplifier :)

Bi-amp with the SSE driving the tweeters (with proper protection) and use the Sansui for the woofers. You can also change the value of the coupling caps in the SSE for a higher cutoff freq when just powering the higher freq drivers. This makes life easier on the amp (and allows additional "apparent" power) since it does not have to pass the higher powered low freq signals.

Taking it one step further, you can throw an active eq between the source and the amps for easy x-over tailoring.
 
Hello sagi4422,

I saw in the pictures placed in post #112 that you are using toogle switch with 3 positions, ie ON / OFF / ON, probably to select UL / Triode and CFB disabling. Is that right? Is there any problem by using these switch?

I´m asking because I put a thread here in the forum and got no convincing answer.
I have some of these switches and would like to use them in the assembly of SSE.

Another question about the toogle switch (red lever) placed on the right side of the rotary switch: is it to select the rectifier mode? Is it a SPDT, On/Off?

Thank you
Sgrilli AD
 
Hello sagi4422,

I saw in the pictures placed in post #112 that you are using toogle switch with 3 positions, ie ON / OFF / ON, probably to select UL / Triode and CFB disabling. Is that right? Is there any problem by using these switch?

I´m asking because I put a thread here in the forum and got no convincing answer.
I have some of these switches and would like to use them in the assembly of SSE.

Another question about the toogle switch (red lever) placed on the right side of the rotary switch: is it to select the rectifier mode? Is it a SPDT, On/Off?

Thank you
Sgrilli AD


Based on comments by some of the more experienced members here, you
should be using separate switches for UL/Triode select and CFB on/off.
Here is a quote from a comment posted by Russ Knize on January 15, 2013

"Power switch and rectifier select is SPST. The triode/UL and cathode feedback switches are DPDT if you want to control both channels with one switch each. A standard 240VAC line-rated switch is sufficient for all. If you choose a switch with a metal handle, be sure the switch body is safely grounded to the chassis."
 
More experienced members already answered your questions.

My advice for you, play a week or two, even more with all the functions without the chassis. Than choose the best configuration per your listening. I rarely use those switches after I found my best conf. and it will reduce dramatically the amount of wiring
 
Thanks to sagi4422 and boywonder,

But ... I think my question was not answered. I just wonder if these 3 positions switch are adequate, because I saw them in the sagi4422 project, or if I need to use some with only two positions (ON / ON).

And ... just to clarify, I will use one switch for each function, certainly.

Thanks again

Sgrilli AD
 
On/on dpdt is ok.
You didn't understand what I meant . I said that consider connect all the switches and functions BEFoRE inserting them into the chassis. Hear how the conf. Influence the sound and decide what is good for you. Than keep only that circuit , without the switches .
For instance , if you like the most UL with CFB , connect it directly without the switch permanently
 
On/on dpdt is ok.
You didn't understand what I meant . I said that consider connect all the switches and functions BEFoRE inserting them into the chassis. Hear how the conf. Influence the sound and decide what is good for you. Than keep only that circuit , without the switches .
For instance , if you like the most UL with CFB , connect it directly without the switch permanently

Hi sagi4422,

Sure, I understood what you meant and this is what I will do. To perform the test I will need the switches, then this is the reason for my question.

Thanks

Sgrilli AD
 
But ... I think my question was not answered. I just wonder if these 3 positions switch are adequate, because I saw them in the sagi4422 project, or if I need to use some with only two positions (ON / ON).

And ... just to clarify, I will use one switch for each function, certainly.

Thanks again

Sgrilli AD

Sgrilli:

I don't know the answer to your question, but you need to consider what would happen with either or both switches in the "off" position. In either case, you have either the suppressor grid not connected to anything or the screen grid not connected to anything. For the most part, having tube grids floating is not a good idea.

For a couple of bucks, I would just get proper switches, or as Sagi mentioned, determine what mode you like during the build, and wire it that way.
 
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