Little Dot Tube Amps: Vacuum Tube Rolling Guide
Nov 8, 2020 at 2:50 PM Post #12,316 of 12,832

MIKELAP

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Hello, I need a little help. Want to change the volume pot in my Little dot MKIII but I can't get it out, don't want to break anything but I don't know what to do after unscrewing the front panel, the pot seems fit in place by two little brackets, how to get it out without breaking anything?
By the way the pot in mine read 323G 50KAX2, so I was thinking about an Alps blue velvet 50K, right? Thanks in advance.
Did you unplug it ?
 
Nov 8, 2020 at 3:08 PM Post #12,317 of 12,832

gibosi

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5A-152M ... is there anybody that tryied it instead of C3g?
application field is the same and same is the value of Uf=6,3V and similar is If=0,47A ... pin out? I still have to check but looks the same
... and costs very few bucks

As TrollDragon points out, the filament current is higher than the C3g, and might be too much for the LD to handle. And further, even if you were willing to accept the risk, the pin-outs of these two tubes are different, and thus you would need another different adapter.
 
Nov 8, 2020 at 5:26 PM Post #12,319 of 12,832

MIKELAP

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Yeah, I unscrewed that...but the pot doesn't come off...tried to but after some force applied was scared to break something and gave up.
A picture would help
 
Nov 9, 2020 at 3:19 AM Post #12,321 of 12,832

lupoal

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... ok now pls excuse me for the stupid question of the day but... about C3g I can read inside quite reliable site here in Europe: " They show their extreme low distortion only as pentodes. They can be used triode connected, but then gain comes down a lot, and the distortion increases to a level just below triodes like 6SN7." ... so as I'm a true rookie... is the C3g in LD2 used as triode or as pentode?

then... available are... TFK... Siemens... Lorenz ITT.... Valvo ... TFK are crazy expensive, roughly the double then the others... what is the scale in terms of sound quality?
 
Nov 9, 2020 at 8:57 AM Post #12,322 of 12,832

gibosi

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... ok now pls excuse me for the stupid question of the day but... about C3g I can read inside quite reliable site here in Europe: " They show their extreme low distortion only as pentodes. They can be used triode connected, but then gain comes down a lot, and the distortion increases to a level just below triodes like 6SN7." ... so as I'm a true rookie... is the C3g in LD2 used as triode or as pentode?

then... available are... TFK... Siemens... Lorenz ITT.... Valvo ... TFK are crazy expensive, roughly the double then the others... what is the scale in terms of sound quality?

First, Valvo never manufactured the C3g. Only Lorenz, Telefunken and Siemens manufactured this tube.

Second, if the C3g has a shiny black can it was manufactured by Siemens, regardless of the branding.

And third, the only way to know for sure that you have a Telefunken or Lorenz is 1) the cans are flat black, that is, no shine. And two, the maker's logo and text is embossed into the top.

Both of these are Siemens. The newer ones have shiny black cans and white stenciling. The older ones have flat black cans with embossed tops.

2015-10-14 10.09.19.jpg


Again, note the flat black cans and embossed tops


2018-11-21 23.44.16.jpg

So again, all C3g with shiny black cans were made by Siemens regardless of the branding. So don't pay a premium for a shiny-black "Telefunken."
 
Nov 9, 2020 at 10:15 AM Post #12,323 of 12,832

TrollDragon

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They show their extreme low distortion only as pentodes. They can be used triode connected, but then gain comes down a lot, and the distortion increases to a level just below triodes like 6SN7." ... so as I'm a true rookie... is the C3g in LD2 used as triode or as pentode?
All pentodes are strapped as triodes internally on the Little Dot circuit board, you cannot run them as pentodes.
 
Nov 9, 2020 at 5:54 PM Post #12,325 of 12,832

lupoal

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@gibosi

... in practis you are telling me that all the tube with shiny black surface has been made by Siemens, the brand on them doesn’t matter... and because of that they all sound the same... right?

but... between a shiny Siemens and an matt embossed lLorenz... would should I get ?

I’ve seen mat black Telefunken, not embossed brand, reach crazy price level... double then Siemens ... mah
 
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Nov 9, 2020 at 7:49 PM Post #12,326 of 12,832

gibosi

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@gibosi

... in practis you are telling me that all the tube with shiny black surface has been made by Siemens, the brand on them doesn’t matter... and because of that they all sound the same... right?

but... between a shiny Siemens and an matt embossed lLorenz... would should I get ?

I’ve seen mat black Telefunken, not embossed brand, reach crazy price level... double then Siemens ... mah

Yes, all C3g with shiny black cans sound the same. They were all made by Siemens.

And in my experience, the flat black Telefunken sounds about the same as the Siemens. I would say that the TFK have a bit more treble presence than the Siemens, but othewise sound very similar. And in my opinion, the difference is so small that the TFK are not worth the extra money.

So now the decision is between flat black Lorenz and shiny Siemens. They sound very different. The Lorenz has more bass presence and generally speaking is darker than the Siemens. So how to decide? Since the Siemen are less money, I suggest that you get a pair. And if you like them, relax and enjoy. But if you discover that you prefer a darker sound, then you can patiently wait for a pair of Lorenz to appear for a decent price.

Good luck! :)
 
Nov 10, 2020 at 1:11 AM Post #12,327 of 12,832

lupoal

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thanks a lot! :)

... and/but... what about this question here: " ... but so if I can’t run them as pentodes ... is the gap in price ( cuouple of tube is about 140 bucks and two adapters are about e5 bucks) compared to 6HM5 jugo justified by much better performance? "

this is my last question then I promise I stop :dt880smile: (till my next one that still have to popup in my mind :grin:)
 
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Nov 10, 2020 at 4:36 AM Post #12,328 of 12,832

triod750

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I use a pair of flat black Siemens C3g and would never go back to yugo 6HM5. To me, the difference is well worth the money. They make my acoustical music much cleaner and more authentic. If I find a Lorenz pair at a decent price I will buy them too. This far, I have mostly been using various 6SN7 with C3g but lately the Melz 6H12C/6N12S has been my preference. They use the same adapter. Melz 6H8C/6N8S is a somewhat lean and very clean Russian version of 6SN7. I am eager to try these with the Lorenz C3g as I expect them to be a very good combination to suit my taste. I have also tried 5687 as output tubes. I like them better than the 6N6P. They are good and powerful but I much prefer 6N12S that are electrically close.

But it is all a matter of preference. And it is fun to experiment.
 
Nov 10, 2020 at 6:58 AM Post #12,329 of 12,832

lupoal

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... I placed my order for two lightly used Siemens (90 USD + 10 USD for shipment)... I thought, as Gibosi indicate, the Lorenz be maybe too much bassy for my taste... at least with Sylvania or Marconi (waiting for them from Canada)... I have some doubt about how Siemens will work with Tungsol... the 6H8C (Foton) are really punchy, with powerful bass, and clean, maybe for them Lorentz is better, we will see

1605009824770.png


1605009874650.png


now I have to try to solve a problem with the power supply... at my home instead of 230Vac I have 240Vac... that give me at the tube 6,7 instead of 6,3... ok 6,3 +/-5% is 6,7 but this is exactly the operating limit specify in Siemens and Telefunken data sheet, for voltage higher then that (slightly higher?) the expected life is specify less then the 10.000 hours otherwise guarantee... uff
 
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Nov 10, 2020 at 8:16 AM Post #12,330 of 12,832

triod750

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... I placed my order for two lightly used Siemens (90 USD + 10 USD for shipment)... I thought, as Gibosi indicate, the Lorenz be maybe too much bassy for my taste... at least with Sylvania or Marconi (waiting for them from Canada)... I have some doubt about how Siemens will work with Tungsol... the 6H8C (Foton) are really punchy, with powerful bass, and clean, maybe for them Lorentz is better, we will see

1605009824770.png

1605009874650.png

now I have to try to solve a problem with the power supply... at my home instead of 230Vac I have 240Vac... that give me at the tube 6,7 instead of 6,3... ok 6,3 +/-5% is 6,7 but this is exactly the operating limit specify in Siemens and Telefunken data sheet, for voltage higher then that (slightly higher?) the expected life is specify less then the 10.000 hours otherwise guarantee... uff

I would not worry about the voltage. I have 242 - 245Vac and have been running tubes on that voltage for years with no trouble. All
you have to do is to restrict your listening to about 24 hours/day, no more :sunglasses::stuck_out_tongue_winking_eye: .

Good luck!
 

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