[JazzVinyl]

And then a week or so after that I will start comparing the amps head to head.

Very much looking forward to the head to head amp shootout

 

[Shane D]

Still going with my MK9 testing. Liked all of my DD headphones on it (Grado GH2's, Focal Elex's, Focal Elegia's, CFA Cascades and LSA HP-2's.

Started today by changing the amp to high gain and plugging in my T60 Argons. I am getting great volume at 1:00 (60 on the dial), but have to go to 2:00 (70 on the dial for older/softer music. To be specific, my ideal volume maxes in the low 70's, decible wise.

I thought I might be missing some punch, so I turned the Schiit Loki on. Of course I have to reduce the amp volume by 10 points to keep it comfortable.

Not sure about the Loki. I decided to go back to my test list and run through it twice, without and without the Loki engaged. Maybe even a third time with the stock drive tube? That is getting excessive, but...

 

[triod750]

I made another temperature comparison. First I measured a pair of Melz 6N12S in my MKIVSE. They need 0,9A for their heaters. Temp on top of the glass is 117C after one hour. I then changed to a pair of T-S 6BX7GT and since they need 1,5A for their heaters I used an external heater psu for them. Temp on top of glass was 88C. A lot cooler! So I expect there are more things at play than heater current. Next I will feed the Melz tubes from the external psu to adjust the comparison.

(I should add that I now use a pair of K-R 6J5 for input, another difference).

 

[JazzVinyl]

Yes I used to externally heat the 2x 6as7g’s in a Felix Elise and indeed major cool down. The Transformer supplying that 2.5 amps per 6080/6as7g also gets warm and its heat (in the Elise) stayed inside the amp….

 

[JazzVinyl]

Look what arrived, today

 

[Shane D]

Tube rolling is now awesome. I have had several hybrids and this is my third "full" tube amp. I never really understood the religious zeal with which a lot of people swap tubes. I have found differences marginal at best.

Until now. You can make a night and day difference with drive tubes on this amp. Thick and bassy is lots of fun until it is too thick after a few days. Then another tube is fresh and clear until after a few days and it seems too bass light.

I can definitely see hunting for a tube that is bassy, yet open. You can probably go broke chasing this dragon.

 

[JazzVinyl]

Still going with my MK9 testing. Liked all of my DD headphones on it (Grado GH2's, Focal Elex's, Focal Elegia's, CFA Cascades and LSA HP-2's.

Started today by changing the amp to high gain and plugging in my T60 Argons. I am getting great volume at 1:00 (60 on the dial), but have to go to 2:00 (70 on the dial for older/softer music. To be specific, my ideal volume maxes in the low 70's, decible wise.

I thought I might be missing some punch, so I turned the Schiit Loki on. Of course I have to reduce the amp volume by 10 points to keep it comfortable.

Not sure about the Loki. I decided to go back to my test list and run through it twice, without and without the Loki engaged. Maybe even a third time with the stock drive tube? That is getting excessive, but...

I like your slow and deliberate approach to running the MK 9 through its paces.

Have noted the Arcturus (RCA) tube did not float your boat, so much?

There are some other tube brands that you should try.

Tung Sol and National Union immediately come to mind.

 

[JazzVinyl]

Tube rolling is now awesome. I have had several hybrids and this is my third "full" tube amp. I never really understood the religious zeal with which a lot of people swap tubes. I have found differences marginal at best.

Until now. You can make a night and day difference with drive tubes on this amp. Thick and bassy is lots of fun until it is too thick after a few days. Then another tube is fresh and clear until after a few days and it seems too bass light.

I can definitely see hunting for a tube that is bassy, yet open. You can probably go broke chasing this dragon.

Tung Sol BGRP
RCA Gray Glass
Ken-Rad
National Union

Get those (you already have a great Sylvania) and you will have all the flavors you need.

Doing National Union here, tonight…it oozes “quality”….

.

 

[Shane D]

i like your slow and deliberate approach to running the MK 9 through its paces.

i have noted the Arcturus (RCA) tube did not float your boat, so much?

There are some other tube brands that you should try.

Tung Sol and National Union immediately come to mind.

I have to get back to that tube. As I recall it is in between the other two. I want to finish All the headphones and then start going amp vs amp. And then more tube rolling. I am dragging this out for months! No more snap decisions.

 

[jonathan c]

Tube rolling is now awesome……..You can will probably go broke chasing this dragon.

FTFY…[Reg. TM; © bcowen: 2021].

 

[JazzVinyl]

Here is my setup...

Externally heating 12SL7's with clean DC voltage. Socket saver in driver position does not have pins 7 and 8 connected, there are 2 wires coming out of the socket saver, to bring in the DC to heat the driver.

Running a 12SL7 National Union, that I knew from other amps I have owned that I would love....and I do!
Lot's of other quality 12SL7's here, but going to take a lesson from @Shane D and go slow....really getting to know the driver well before switching.

Using ZMF Aeolus, had to go straight for the High gain position for these 300 ohm cans.

I am loving what I am hearing...I did add the home made tube damper because SL7's at 70mu are known to be a bit micro-phonic...it is a slice of a dollar store pool noodle...as are the dampener "feet" for the amp. Wanted it up in the air a bit, to catch some air from the fan, and so I could feel about under the amp to see if it was getting hot. Use of the fan and all is well...no heat worries at all.

Source is a battery powered DAP...Shanling M6 running Power Amp software that has bass/treble and "reverb" and "widening" which I love

 

[st939]

And what's your serial number out of curiosity?

 

[JazzVinyl]

And what's your serial number out of curiosity?

No. 721

 

[JazzVinyl]

Hello @st939 -

Are you still running No. 62 with the Tung-Sol 5998's and your lovely RCA 5691?

 

[Shane D]

And what's your serial number out of curiosity?

Not that you asked me but, my new amp is Ser. # 922.