Much of the Way an Amplifier Sounds
Depends on whether we listen to the program material, music, Etc or we listen for the artifacts, the problems. Or perhaps the amp is built to look at, complete with obscure parts to impress our friends. So today I went cross country skiing, right out the back door. Perhaps tomorrow will be the day to plug the soldering iron in again. And listen to my home brewed in 1968 completely integrated 3W amp. With its feedback pair 6AU6/6AQ5 amp driving a replacement auto speaker in a sealed box.😀 And no boutique parts. At all!😱
Depends on whether we listen to the program material, music, Etc or we listen for the artifacts, the problems. Or perhaps the amp is built to look at, complete with obscure parts to impress our friends. So today I went cross country skiing, right out the back door. Perhaps tomorrow will be the day to plug the soldering iron in again. And listen to my home brewed in 1968 completely integrated 3W amp. With its feedback pair 6AU6/6AQ5 amp driving a replacement auto speaker in a sealed box.😀 And no boutique parts. At all!😱
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Well guys I want to thank each one of you for your input and advice, the idea here is for me to decide on an amp that uses cheap tubes that sound as good as the pricey ones. I been using a 45 type amp for years with the EML solid plates but, at 63 years old I can not afford to replace them when that time comes. So I am just trying to get ahead of when that happens and have an amp ready to replace my 45 amp...
Just a thought, if the filament supply of your 45 amp can support 2.5A, then it can be used with a more affordable 2A3 biased at 45 bias current.
indra1,
I agree.
You took the words right out of my mouth!
If a new filament supply is needed, and if it will fit, then that can be modified to accommodate the extra filament current.
If it will not fit, put all the parts on a new chassis.
The EML 45 is probably as close to a 2A3 as it is to a 45 (the EML model that has the extra plate dissipation).
I agree.
You took the words right out of my mouth!
If a new filament supply is needed, and if it will fit, then that can be modified to accommodate the extra filament current.
If it will not fit, put all the parts on a new chassis.
The EML 45 is probably as close to a 2A3 as it is to a 45 (the EML model that has the extra plate dissipation).
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Great idea, only problem with that is the EML 2A3 tubes cost more than the 45 tubes!!! Yikes!!!
jcmusic,
Can you Post a Schematic of your amplifier, Please?
There are lots of current production 2A3 tubes available.
Many of them are extremely good sounding.
Do not replace an EML 45 with an EML 2A3.
Instead pick a different manufacturer's 2A3.
I am sure some readers of this thread will recommend some good brands of current production 2A3 tubes.
The 45 has 1.5A filaments.
The 2A3 has 2.5A filaments.
You can temporarily put a filament transformer outside of your amplifier chassis, just to try one of the 2A3 tubes, or a pair of 2A3s.
Increase the grid bias voltage until the plate current is the same as the EML 45 was.
Or if it is a self bias circuit, increase the self bias resistor value to get the same current; and replace the bypass cap with one of a higher voltage if the new self bias voltage requires it.
This part is relatively easy.
Then, Listen, Listen, Listen.
If you like what you hear, you can decide if the new filament transformer(s) can be mounted on the old chassis, or if you need a new chassis.
If you need a new chassis, that is the hard part, lots of work; but when you are done,
now your worries are over.
Can you Post a Schematic of your amplifier, Please?
There are lots of current production 2A3 tubes available.
Many of them are extremely good sounding.
Do not replace an EML 45 with an EML 2A3.
Instead pick a different manufacturer's 2A3.
I am sure some readers of this thread will recommend some good brands of current production 2A3 tubes.
The 45 has 1.5A filaments.
The 2A3 has 2.5A filaments.
You can temporarily put a filament transformer outside of your amplifier chassis, just to try one of the 2A3 tubes, or a pair of 2A3s.
Increase the grid bias voltage until the plate current is the same as the EML 45 was.
Or if it is a self bias circuit, increase the self bias resistor value to get the same current; and replace the bypass cap with one of a higher voltage if the new self bias voltage requires it.
This part is relatively easy.
Then, Listen, Listen, Listen.
If you like what you hear, you can decide if the new filament transformer(s) can be mounted on the old chassis, or if you need a new chassis.
If you need a new chassis, that is the hard part, lots of work; but when you are done,
now your worries are over.
Looks like that 1968 All-In-One amp has many hits, so here is the AudioXpress article covering it in some detail .🙂