• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

Looking for a 45 SE Schematic

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rcdaniel

Member
Joined 2002
Hi KM

Thank you v much for sharing your views regarding NOS vs new prod'n tubes, specifically the EML45. Many experienced folks prefer the EML to NOS, others prefer NOS over the EML, yet others prefer the Shug' 2A3C at 45 O.P.s over the EML... I guess at some point context and personal preferences matter.

Personally, it seems there are some very nice tubes being made these days; I look forward to building an amp soon and playing with a couple. Now, if I could just decide on what to build...

Cheers
 
V

Vlauga

Member
Joined 2005
rcdaniel said:
* Current(ish) type 50 production:

Have not heard much re the TJ and not sure of their approach to constrution (I have read that TJ supposedly have two main approaches, with one generally preferred over the other - but that could be total BS).
Click to expand...

Do not plan for your design of a valve of manufacture TJ!

These people exclusively illiterately develop the tubes. With intolerable errors for the vacuum-tube technics.
As a result you do not gain qualitative sounding.
Also a resource of these tubes extremely small.
Will transit one year, and issue will decrease critically.
I observed it for two tubes TJ: 50 and PX4.

TJ50 sound carelessly.
RCA50 sound incomparably better.
But 45 tube sounds even better)
Though it does not have such massive bass, as at 50 tubes.
PX4 and PX25 sound more pathetically. It is more than details, a shock bass.
 
V

Vlauga

Member
Joined 2005
Here look, please.

An externally hosted image should be here but it was not working when we last tested it.


An externally hosted image should be here but it was not working when we last tested it.


An externally hosted image should be here but it was not working when we last tested it.


An externally hosted image should be here but it was not working when we last tested it.


It TJ PX4.
At it the cathode represents letter M.
And it is located only in the central part of electrode system. It very narrow.

An externally hosted image should be here but it was not working when we last tested it.


An externally hosted image should be here but it was not working when we last tested it.


It is exact remark PX4 from the fiftieth years. You see, how many there cathode hairlines!
 
F

funkytek

Member
Joined 2008
korneluk said:
Kevin, et al,

At the risk of getting run out town for hijacking this thread, here's a preliminary design for an all-DHT 50 amp. The tubes were purposely chosen to voice the amp and balance out the darker sound of the 50.

Note that the power voltages are not optimized - this is a "paper design" little more than a cleaned-up sketch.

Enjoy,

-- josé k.
Click to expand...

Hi Jose,
I played with the 801 and 46 quite a bit in the 90's. I always found them to be lush and warm (in my designs). So I would expect this amp to be very very warm sounding. From this perspective I thought it was interesting that you would choose these to balance a dark sounding output...

Definitely an interesting idea though. I really like both the 801 and 46. I have used the 46 as a driver before, but I have never used the 801 as an input! Cool.
-grego
 
JLH

JLH

Member
Joined 2005
korneluk said:
Kevin, et al,

At the risk of getting run out town for hijacking this thread, here's a preliminary design for an all-DHT 50 amp. The tubes were purposely chosen to voice the amp and balance out the darker sound of the 50.

Note that the power voltages are not optimized - this is a "paper design" little more than a cleaned-up sketch.

Enjoy,

-- josé k.
Click to expand...

That is a totally sick design. I wish I would have thought of that. Knowing the tone and voice of the tubes you chose, I can see exactly what you are trying to do. That could also work for a 300B. However, like you said the 50 is a bit dark sounding. I'm thinking for more power and proper tone you might be able to sub in one of the newer carbon plate 300Bs. Either way, very nice design. I like it.

Rgs, JLH
 
kmaier

kmaier

Member
Joined 2007
Ty_Bower said:
Is the JE Labs Simple 45 worth a mention?

simple45
Click to expand...

But of course... as is Gordon Rankin's Bugle (earlier in this thread). In fact, I recommend his Bugle article as baseline reading for good insight on driving the 45 and DHTs in general.

I prefer having a lower impedance drive to the 45 with more current capability and a higher slew rate. My input/driver circuit will push a very clean 10KHz square wave into the 45 grid with no ringing and no noticeable slew problems. See scope pic below... upper trace is the feed to the input of the amplifier, lower trace is directly at the 45 grid at 100 volts pk-pk.

An externally hosted image should be here but it was not working when we last tested it.


Regards, KM
 
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