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45 tubes for Yamamoto A-08s

I am new to this type of tubes, i said to myself never buy tube amp anymore, but it was hard to resist when Yamamoto A-08s (from my old wantlist) turned up for sale at affordable price, finally. And i bought it (no more cartridges this month for sure, i am saving on new tubes). 

So many amazing reviews online, especially from people who use same speakers like my Zu Audio Druid.

Damn, why do i need another amp if i already have First Watt praised as much as the Yammy with same type of speakers. Maybe for my final comparison of the best Solid State vs. SET ... who knows.

Anyway, my unit comes with used tubes supplied originally (NOS) by the manufacturer.

I know nothing about 45 tubes and i wish to learn quickly.

The most popular NEW replacement is Emission Lab 45s ($648 for a pair in USA now, the price will be higher soon).

Maybe there are some cheaper NOS tubes available ?


Please recommend me something, especially if you have same Yamamoto A-08s amp

Thanks!


128x128chakster
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chakster OP
6,144 posts
 
To my surprise i have plenty of gain with my passive Pass ALEPH L preamp with Yamamoto A-08s, this combination with Zu Audio Druid is shockingly good.

I was a little bit afraid that with 2w single ended i will need some active gain stage, but i was wrong! No need for any active gain stage in this combo (even in my big room). If someone thinking about active gain stage with this amp i must say with 101db speakers and some nice phono stage the active gain stage is a waste of money for nothing. Only passive preamp! I love Pass Aleph L because there are 4 inputs and 2 line outputs. 

Still listening with the stock vintage NOS tubes provided by the manufacturer.

But luckily got my NU 45s (from USA) and Rectifier 80 (from Australia) back up before covid-19 situation.


sdrsdrsdr
196 posts
 
I have experience with passive line stages. Basically it’s just a volume control. My first was using the digital volume control in my dac back in the 90’s. I’ve also used extensively resistor and transformer based. Including  two from Bent audio and a Placette.  Most SET amps are easy to drive and work fine this way. Some push pull, but not usually as easy. 

I wouldn’t agree that an active preamp is a waste of money. For the price  a passive is a good choice. But in my much experience a quality active preamp will give much more performance than a passive. My experience was comparing to my Atma-sphere Mp1 years ago. Many times more costly too. There’s more to an active preamp than gain. Usually your source  is putting out more gain than you need. If your listening just for detail and lack of distortion,  a passive is hard to beat though. 

chakster's avatar
chakster OP
6,144 posts
 
@sdrsdrsdr yes, my concern was only about this particular combo, the reason i asked before for Yamamoto preamp than nobody tried, i realized that it will be overkill for my 101db speakers. 

Pass ALEPH L preamp available in several versions, the one i have is passive when the volume control in under 3 o'lock, then it will be an active pre if the volume is more than 3 o'clock. Clever design from Nelson Pass. With my speakers and this Yamamoto A-08s (2w) i don't need an active gain for sure, hard to believe, the volume control on my pre is under 12 o'clock (and this is god damn loud). 


sdrsdrsdr
196 posts
 
Yes. Like I said. Your source is more than enough gain for your Yamamoto to be driven. Probably would  be too much wide open. I used to have one of those myself, the Yamamoto, years ago. Along with a 300b and 845 amp that I used when I had  my Avantgarde Trios. They are excellent. I still own a 45 amp that I use when I put my Lamhorn speakers in my system. It’s an Oliver Sayes build that is based on the Korneff design.
chakster's avatar
chakster OP
6,144 posts
 
Since I sold some of the rarest 12at7wa tubes from my ex push-pull amp., I’m thinking about much older 45 tubes from the 1930’s for my Yamamoto A-08s. ST bottle shape or Globes, Solid Plates or Mesh Plates... This is where you lost me... Vintage tubes are addictive, you’d better get rid of them all, or you’re always buying some more. I thought I’m done with the tubes, but I’m still buying more. Stop me somebody ...

After some research these trio is on my radar now:

-RCA 80 GLOBE tube (tested 56/52 where min is 40)
-RCA 245 GLOBES (PAIR) (tested both 66/66 where min is 47)

Any comments?

I don’t have a tube tester, but I hope I can trust a seller who’s got calibrated TV7 tester and life long experience.
Tube testing is another quest, I know nothing about it. Would you buy a tube with tested results stated above?

This is what I received so far from another tube dealer: NOS 717A matched pair (mushrooms).

National Union 45s from another audiogon member.

And this Radiotron 80 from Australia

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