Ref 5 / 5se and different 6550 tubes

[Number95]

Originally Posted by Harlequin

Whilst I'm sure that both replacement types would have added to the performance as a whole , It would be interesting to run through the various combinations as to whether the rectifier or the signal valves brought the larger benefit , or if indeed equal in measure

Jasper.

You are very right

The starting point to swap tubes was original tubes were done so they needed replacement and I decided to try NOS for all parts. I will have a spare Svetlana 6550c so I may try to see the 6550 impact. Only problem is my laziness

[Harlequin]

I certainly look forward to hearing of any experimentation Number's , I just checked the clock on my Ref 5 se = 1 Hour

[MPS]

I think this current topology is not very grateful when it comes to tube rolling. Besides NOS 6H30-DR there is no substitute for signal tubes and 6550 as part of the regulator circuit only has a slight difference to make, it might be wise to stick with what W.Z.Johnson originally planned in to his design.

[Number95]

Originally Posted by MPS

I think this current topology is not very grateful when it comes to tube rolling. Besides NOS 6H30-DR there is no substitute for signal tubes and 6550 as part of the regulator circuit only has a slight difference to make, it might be wise to stick with what W.Z.Johnson originally planned in to his design.

Hi MBS

I dont think it is against any design to use Nos tubes. Most of the manufacturers prefer the tubes within their equipments not based on their superiorities but mostly availabilities. A big company like ARC can not rely on a limited stock of nos tubes. Although I am not fond of experimenting with different brand of tubes, nos etc, my observations with recently swapped tubes of my Ref-3 telling there is an audible difference and it is for good, not a compromise. Should I think of a similar experiment on my Ref 610T monos? Definitely not

[Number95]

Originally Posted by Harlequin

I certainly look forward to hearing of any experimentation Number's , I just checked the clock on my Ref 5 se = 1 Hour

Harlequin, I will let you know if I make a direct comparison between Svetlana 6550c and GE NOS. Now, enjoy your Ref5 SE and do not worry too much for tube rolling, you already have one the best preamps ever built.

[MPS]

Originally Posted by Number95

Hi MBS

I dont think it is against any design to use Nos tubes. Most of the manufacturers prefer the tubes within their equipments not based on their superiorities but mostly availabilities. A big company like ARC can not rely on a limited stock of nos tubes. Although I am not fond of experimenting with different brand of tubes, nos etc, my observations with recently swapped tubes of my Ref-3 telling there is an audible difference and it is for good, not a compromise. Should I think of a similar experiment on my Ref 610T monos? Definitely not

Yes, I totally agree. What I was trying to say is that while Reflektor 6H30-DR could be a good NOS choice, it also is the only one As 6550 is not in the amplifying stage, it also might not be so critical for sound.
I too do think that NOS tubes generally are of higher quality than new production so if you have those why not go ahead and try

[Harlequin]

Originally Posted by MPS

Yes, I totally agree. What I was trying to say is that while Reflektor 6H30-DR could be a good NOS choice, it also is the only one As 6550 is not in the amplifying stage, it also might not be so critical for sound.
I too do think that NOS tubes generally are of higher quality than new production so if you have those why not go ahead and try

Good evening .

Having had varying degrees of positive whilst rolling rectifiers in other circuits I am curious about the 6550 in the Ref 5se .

Pending a few more hours on the clock I have a few NOS valves to play with , 70's Philips , early 60's GE , and have my radar sweeping for an 50's blackplate Tung-Sol.

It is a pity that AR would appear not to recommend/support substitution of the 6550 with an KT-88 , quality NOS regardless .

[Number95]

Originally Posted by Harlequin

Good evening .

Having had varying degrees of positive whilst rolling rectifiers in other circuits I am curious about the 6550 in the Ref 5se .

Pending a few more hours on the clock I have a few NOS valves to play with , 70's Philips , early 60's GE , and have my radar sweeping for an 50's blackplate Tung-Sol.

It is a pity that AR would appear not to recommend/support substitution of the 6550 with an KT-88 , quality NOS regardless .

If I am not wrong, you have a brand new Ref 5 SE which has just started to its burning journey. I recommend you wait to play with different tubes until a serious burning in take place for the unit, since the sound will change -not for the good every time- and gradually improve within time (arc recommends 600 hours critical burning period), assessment of different tubes and their sonic contribution may not be fully addressed. Happy listenings.

[Harlequin]

Originally Posted by Number95

If I am not wrong, you have a brand new Ref 5 SE which has just started to its burning journey. I recommend you wait to play with different tubes until a serious burning in take place for the unit, since the sound will change -not for the good every time- and gradually improve within time (arc recommends 600 hours critical burning period), assessment of different tubes and their sonic contribution may not be fully addressed. Happy listenings.

Good evening Numbers .

That was indeed my plan

[tima]

Originally Posted by Number95

Harlequin, I will let you know if I make a direct comparison between Svetlana 6550c and GE NOS. Now, enjoy your Ref5 SE and do not worry too much for tube rolling, you already have one the best preamps ever built.

The GE 6550A brings little beyond flabby bathos to the Ref 5SE and Ref Phono 2/SE - ime it's a tube to avoid in those applications.

(But a fine tube in several CJ amps. )