Input or Output tube the more Imp while rolling ...

Jazzhead

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• Nov 18, 2013

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What would you say is the more important tube, while rolling a tube amp ? Is it the input or the output tube that is more detrimental to the final flavour . Am sure it is a combination of the two , but in your experience which do you think has the more dominant signature .

So if you were to mix n match a midrange oriented tube with a more linear accurate type , which would theoretically fit the input and which the output .

Best would be to try , given the variables ... yes ... but rolling my pre-amp is a PIA , given that that I have to flip it over and unscrew the bottom plate to get at the innards . This rules out any quick swap comparisons , any thoughts would help me plan accordingly .

 

Last edited: Nov 19, 2013

D

DaveyF

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• Nov 19, 2013

• #2

Probably depends on the particular amp or preamp that you are rolling tubes into. IMO, tube rolling isn't that predictable...I think you have to experiment a little and see what you like.

 

JackD201

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• Nov 19, 2013

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Quickest, cheapest and sometimes more effective because you have such a wider choice of flavors for most popular tube types..........Input Tube

The expense of power tubes makes them much more risky for a first try in a system. Literally 50/50 IMO.

 

Jazzhead

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• Nov 19, 2013

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Just to clarify .. I am talking about input and output tubes in the pre-amp .

 

JackD201

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Ooops

With a two stage design or more In my experience, still the input tube.

 

Jazzhead

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JackD201 said:

Ooops

With a two stage design or more In my experience, still the input tube.

Click to expand...

Thanks , have the Mullard CV 491 0n the output and Psvane on the input , think I'll switch it around . The CV491 sound pretty decent straight off , am sure it will develop further .

 

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zztop7

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• Nov 19, 2013

• #7

The output tube must be excellent, BUT if you feed it a lousy signal, all is lost.
Therefore, the input must be great, and the output must not degrade it but only be neutral or improve it.

zz.

 

JackD201

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• Nov 19, 2013

• #8

CV 491 is one of my favorites. My business partner's as well.

 

Jazzhead

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• Nov 19, 2013

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How about a Mullard CV491 on the input and something linear like a Siemens EC882 on the output ... will try tomorrow and report , sounds good on paper at least

 

DonH50

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• Nov 19, 2013

• #10

The input tube will normally dominate the noise and often the distortion of the pre-amp.

 

Jazzhead

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• Nov 20, 2013

• #11

JackD201 said:

CV 491 is one of my favorites. My business partner's as well.

Click to expand...

How many hours before it starts strutting it's stuff . Any idea while burning in a tube , is it sufficient to keep the amp turned on or is it necessary to have a signal running thru it .

 

JackD201

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• Nov 20, 2013

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If you're fortunate to get NIB, I'd say the bloat goes away after just a few hours with signal going through them. 24 hours tops then enjoy the next few thousand. If NOS and measuring strong, they should be as good as they get already. Just your normal warm up time.

 

Jazzhead

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• Nov 20, 2013

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This is what I got from Brent Jesse , regarding my query on tube-burn in

 

Jazzhead

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• Nov 22, 2013

• #14

JackD201 said:

CV 491 is one of my favorites. My business partner's as well.

Click to expand...

JackD201.... any experience with the Phillips 7316 ,1959 date code ?

 

JackD201

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• Nov 22, 2013

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No Sir, never seen one. Don't have any experience with any Philips tubes come to think of it.

 

MylesBAstor

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• Nov 22, 2013

• #16

Jazzhead said:

JackD201.... any experience with the Phillips 7316 ,1959 date code ?

Click to expand...

Bought some never tried them. 7316 supposed to be one of the best.

 

JackD201

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• Nov 22, 2013

• #17

When you get a chance to try them, give us your impressions please Myles.