[Whitigir]

Yeah, Cayin knows their stuff well

 

[baronbeehive]

Yet the Cathode cap is another story.
I always see wide range of values.
Just the other day I worked on a Cayin HA-300, and it has only 100uf(!):

I wonder if it is deliberately to get a certain sound signature?

The LD has 220uF and that maybe for greater transient recovery as compared to 100uF. Maybe because it doesn't have the control of an OT?

I wonder if, looking at the cathode calculator graph where 100uF looks good enough to all intents and purposes that maybe we are going in for overkill with 470uF +, yet the greater capacitance should allow for greater transient recovery, so long as it is not so high as to mask the higher frequencies with mega bass!

I regard Cayin the absolute best, at making euphoric sounding amps, without the harshness of unwanted harmonics.
They are genius, when you observe their parts choices...

While I regard Little Dot path, is to use more of "design choices", rather than parts choices, for their sound. Just looking at the bias points of the driver stage, is a prime example.

You're probably right, different makers favour different parts choices, and I think it was Cayin that used pure silver internal wiring also? Yet LD make do with tin wire... yuck .

But the earlier MKVI's, of which I have one, had better quality Dale resistors which were swopped out for cheap versions later! And the blue power and PSU resistors were abysmal .

 

[Whitigir]

I would use pure silver wiring where I can, but they are not cheap, and not all silvers are made the same. What Cayin is using pure silver internally ?

 

[Maxx134]

Definitely for bass hits (current drain) we need more capacitance, because this is not a traditional transformer output, or even a traditional circuit, being WCF design.
So we are relying heavily on the tubes for all of the power...

 

[baronbeehive]

I would use pure silver wiring where I can, but they are not cheap, and not all silvers are made the same. What Cayin is using pure silver internally ?

Yes internally. I can't remember if it was actually them TBH, but one of those Chinese makers, may have been Yamamoto.

 

[Maxx134]

We need to focus on the output stage caps.
The cathode cap is still before the WCF stage.... So any cathode current drain, would be from those tubes only, not the headphones load(?), hmmm

 

[Maxx134]

Ok, so on first page, according to Ridge78, half the current of the WCF push/pull design, comes from the cathode caps(!).

So now, what about the WCF cap between the triods? Have we been overlooking these?

 

[baronbeehive]

We need to focus on the output stage caps.
The cathode cap is still before the WCF stage.... So any drain would be from those tubes only, not the headphones load, hmmm

@CopperFox uses 100uF Wimas there, (decoupling). Also for driver stage decoupling but I think my 40uF are adequate there.

 

[baronbeehive]

Ok, so on first page, according to Ridge78, half the current of the WCF push/pull design, comes from the cathode caps(!).

So now, what about the WCF cap between the triods? Have we been overlooking these?

Maybe, we haven't touched those!

 

[baronbeehive]

Maybe, we haven't touched those!

Also he uses 400uF PSU film caps which could be good there, I haven't decided.

 

[Maxx134]

It sucks that all the original pics are gone from first page. I have most but it will take time to find and re-upload.

 

[Maxx134]

Maybe, we haven't touched those!

Actually we did. I believe you used mundorf there .
My issue is I am wondering about current drain, as caps used as output caps are large (for current), and not have anything to do with frequency, so although as only 220uf was needed here (stock) for frequency....

I'm wondering if more capacitance would help here with transients...
Because the cap is in series with output flow, just like an output cap...

 

[Maxx134]

I'm guessing a test with a paralleled electrolytic here would find out...

 

[baronbeehive]

It sucks that all the original pics are gone from first page. I have most but it will take time to find and re-upload.

I know and it's no fun reading up on all that any more .

 

[baronbeehive]

Actually we did. I believe you used mundorf there .

Sorry for the momentary lapse.. for some reason I was thinking of those original small Wimas that were there before we replaced them. I did use Mundorf and I only realized recently that they were film caps, polypropylene metallized with silver as opposed the the MKP Mundorfs we used for decoupling which were polypropylene metallized with aluminium.

Actually we did. I believe you used mundorf there .
My issue is I am wondering about current drain, as caps used as output caps are large (for current), and not have anything to do with frequency, so although as only 220uf was needed here (stock) for frequency....

I'm wondering if more capacitance would help here with transients...
Because the cap is in series with output flow, just like an output cap...

I don't like to admit it but you must be right, the WCF being just as important as the cathode caps, my problem is I don't really understand the maths behind the WCF.

So maybe bigger caps like the Mundorf Supreme SIO that I have... only bigger.... much... BIGGER..... .