46 tube - Could I live with 1.25 watts?

adaug

Awaiting Updated Member Status.
Amazing post. Thanks🙏🏼
ditto. i also have an amp that flexes b/w 45s and 2A3s, but its been a while since ive used it with 45s. dont have speakers that i "think" will work well w 45s. but the only way to really know how 45s will work with them is to try it - in audio there are surprises.
 

Thermionics

Post Whore In Training
For the record, I am running a pair of Heresy III clones driven by a 1626 Darling amp (750mWPC) in my garage, and it gets plenty loud. And we’re talking head-banging music while I work on projects.

I think you should be fine with 1.25 WPC.
 
I have been using a 45 tube for 3 years, about 95% of the time. I read forums and people will say you are listening to distortion if you turn it more that 20%, or something like that. It makes me feel like I'm doing it wrong. So I'd try other more powerful amps and tubes. I used a 300b before the 45 and I kept it around for years just in case. Then I bought a First watt J2. Same thing... try more power. I keep going back to the less than 2 watts. Now I wanna keep going lower. Keep drawing a new line in the sand. What the heck is next? thanks for all the input. 🙏
 
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I keep going back to the less than 2 watts. Now I wanna keep going lower. Keep drawing a new line in the sand. What the heck is next? thanks for all the input. 🙏
I'm running a pair of blue Arcturus 71A globes and once they get dialed in, they are surprisingly good enough such that I'm aiming at getting a set of dialed in OPT's, just to see how scalable these tubes (along with the rest of the system) really are. :chin

But at this level of power either you have REALLY efficient spkrs or are running efficient HP's.

Mostly because when it sounds so enticing like this, the need to have to crank on it becomes more a matter of just how far you want to push it into clipping… :confused:

That is one distinct advantage to running HP's, I can crank on it well into ear bleed levels, while running full range+ (subsonic to well beyond 20KHz), since there is only one driver, all on 0.75w/ch. :cool:

JJ👍
 
Ok, a contrary opinion from a contrarian. :)

I have not heard a 46 amp, but own and LOVE a 45 capable amp - which should have around the same 1.5w of output power. I use it on 100db sensitive Altec 604s and even rely on separate powered helper woofers for the low bass, so when all put in a normal sized listening room of 13 x 21, think I'm giving that little amp as good a chance as I can to do it's thing - short of using even more efficient all horn speakers that just aren't appropriate for my small room (IMO).

With some switch selectable internal changes, that same 45 amp can use 2A3s (3w?), and I've been through many 300B (6w?) amps, so have 100's of hours of comparison in between these 3 approaches, or at least the implementations of them I've had in my system. Lots of time to draw conclusions and almost all of these amps have sounded 'good', so it's been a joy trying to decide which best suits me.

And "me" is the key; this is SO personal with so many variables like speakers (!!!), room, musical preferences, usual listening level, etc. that only you can make the call if 1.5w is enough.

The 45 is my all time favourite tube so far, especially with Jazz, some Americana and Blues. With the right recording; mesmerising presence, flesh and blood in the room, real full-scale instruments playing in interesting acoustic spaces that erase the room walls - the "psychedelic...pink cloud" Guf speaks of. On a regular basis, I'll flip the amp, set it for 45s and pop in my favourite pair (RCA globe 245) to get lost for a while. I love what this tube can do.

But for me, 1.5w is not enough.

My musical tastes are all over the place, and eventually I'll want to listen to something that makes the little 45s sound strained, soft and closed in, losing their extension & magic. The pink cloud starts to fade and darken, and it's time for the change back to my sweet-spot - the 2A3. With good tubes (I really like RCA bi-plates and even JJs), the 2A3 amp setup gets very close to the 45 with much of the technicolor trip, along with the balls (sure, 3w of balls... :D) to better handle some Blues, Rock or big scale orchestral. This is the perfect daily-driver for me and I don't even think about 45s that much.

And now that I've said that, I think I need a hit from the 245s today. :)
Interesting post.

Since you are using a separate amplifier for the woofers, are you saying the sound loses top-end extension? That would be surprising because what I usually associate with a lack of power is compression and reduced output in the bass region, not the treble. The compression driver in your 604, presumably with a resistive attenuator, should not present the same impedance challenges as a woofer.

Wonder if others have experienced the same thing - what does a lack of power sound like?
 

billfort

Administrator
Staff member
I spent a lot of time getting the SET amp>passive crossover>604 combination to where I liked it - I found it best to just leave that all alone when I added 'helper' woofers (a separate pair of 416As) for deep bass. I messed with additional active and passive filters in front of that part of the system, and nothing sounded as good as just letting the SET amp feed to 604 straight-up, full-range. When used like this, a 45/2a3/300b has to do it all whether the helpers are on or not.

There is the nice side benefit of the main amp>604s not having to carry the full load in the deep bass though, so I have more flexibility to optimize that part of the system for upper-bass on up and imaging. The speakers came out of the corners & away from walls, I started using coupling caps I thought sounded better in the mids and treble and I settled on the old 245 globes as my 45 go-tos - they do everything better - other than the bass. They still play full-range though, and 1.5w isn't enough for me across the board.

No right or wrong here, just my decision using my ears in my room.
 
i have a couple pair of the globes and about 4 pairs of the st. I have read that the st sounds better, but I cannot verify that, I have been using the globes for the past year And really liked them a lot. They are getting more expensive and harder to find these days.
 

Thermionics

Post Whore In Training
FWIW, I am slowly gathering the bits and bobs for a 46 amp. However, at some point the 46 tube got expensive!
 

adaug

Awaiting Updated Member Status.
I use my 45 set amp with 46 globe all the time. I have more 46 tubes than I do 45.
using an adapter, right? and do you have to change any of the parameters of the 45 set amp to work with 46s?

thanks
 
Yes an adaptor, and my amp parameters are still for the 45. Here is an old article to use the 46 in a 45 amp and other adaptors. I have not had any issues with the 46 tube in my amp.

D4E94369-C0BB-4CB1-8A26-49CF20B7398C.jpeg
 
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Thermionics

Post Whore In Training
Well... I have been living with the awesome power and sound of the single-ended Type 46 for over six years, ever since I finished these...



Hey, Nate - could you please post the schematic for this amp?


(tagging @Redboy for visibility)
 
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Yes an adaptor, and my amp parameters are still for the 45. Here is an old article to use the 46 in a 45 amp and other adaptors. I have not had any issues with the 46 tube in my amp.

View attachment 34150
Does anyone know where you can purchase these adapters? The article is from the July 1933 Popular Science magazine.

 

adaug

Awaiting Updated Member Status.
Yes an adaptor, and my amp parameters are still for the 45. Here is an old article to use the 46 in a 45 amp and other adaptors. I have not had any issues with the 46 tube in my amp.
thanks for this. along the lines of the prior response, did you build or purchase the adaptor?
 
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