SE 45 tube amp and tubes available

[atmasphere]

I'm working on a 45 amp that uses a filament supply that is simply derived from a resistor dropping the Voltage from a 6.3V filament supply. The amp uses a converted Wurlitzer organ amp chassis.

DHTs being what they are, seems to me the filament Voltage is critical; something a simple resistor won't do. I've found that various 45s express a different amount of filament current, thus causing the Voltage to change too.

I found a DC to DC converter on Mouser that makes 2Amps at 2.5V. It can take roughly 5-25VDC as an input. So I'm using some rectifiers from that 6.3V supply to make a DC supply that should do the job. The converter is tiny! It regulates so hopefully the 45s will behave better with that as a supply and it might hum less too (or not at all)- always helpful when the amp is such low power...

 

[gadget73]

DC heat on a DHT just seems not quite right to me. Maybe its not as big a problem in reality as it seems in my head but with one end of the cathode effectively being more negative than the other by 2.5 volts, it just seems like it wouldn't emit equally and that has to do something to how it performs.

and yes I know early DHT were frequently used on batteries, so DC supply.

 

[tubeactive]

Push-Pull 45s and 2A3s can easily use AC filaments, with very low or no hum heard.
DC filaments do change their sound character, imho...

 

[gadget73]

Are 50 tubes being made now? Those were pretty short lived back in the 30s and when you find one they are either big money or used up.

I like the woodwork

 

[buglegirl]

Are 50 tubes being made now? Those were pretty short lived back in the 30s and when you find one they are either big money or used up.

I like the woodwork

Apparently they are but I have not tried one so don't know how good they are.

EDIT:: Also not entirely sure they are easily avaliable

DHTRob - Shootout type 50

Frannie

 

[gadget73]

occasionally I wonder if things are good because they are good, or if they are good because they are rare. Its that whole "I want what I don't have" deal.

 

[buglegirl]

occasionally I wonder if things are good because they are good, or if they are good because they are rare. Its that whole "I want what I don't have" deal.

Well what fun would there be in being happy with what we have already.

Frannie

 

[buglegirl]

Hiya,

IMHO the best DHT is the 2A3 (Higher wattage , easier availability and more reliable)

Reasonable old stock and a wide range of new production tubes to choose from.

As far as sonic comparison to the Type 45/46 I don't know to be honest.

Frannie

 

[gadget73]

I was referring specifically to the 50 tube, not the amp.

I've never heard of this person before, but that doesn't really mean much. If its not decades old, the chances of me having ever heard of a thing diminish greatly

 

[Mike Stehr]

I dont know, but just looking at what he builds, those are no joke works of art and will cost you $8500 and a long wait

That's the kind of money you pour into a ride, not an amp...unless you want that bling factor.
Have you ever thought about building a tube amplifier?

 

[tubelectron]

As far as sonic comparison to the Type 45/46 I don't know to be honest.

I think that I have a pair, or maybe a quartet of NOS 46 tubes - I'll have a look to that.

T

 

[x3workshop]

Dennis Had's builds are excellent. I own one of his parallel 45's and it is a glorious sounding amp paired with the right speakers.

As to whether globes sound better than ST, I have used both with different speaker pairings and tend to prefer the ST RCA's.

I have not tried the EML 45's, but will likely spring for a quad down the line. They come with a 5 year warranty for everything except wear and reports are that they last a very long time.

 

[Selmerdave]

I do know someone with a great deal of experience building and designing, and the 50 triode is their favorite tube for sonics, though they use 2A3s themselves for the aforementioned reasons of cost and availability. They have built dozens of 50-based amps for customers though.

 

[Lucky Pierre]

Just this year I ventured into SET 45 tube land. I will never leave. ~2 watts of 45 goodness on my RCA SL-12D in Jensen cabinets is total audio bliss. And I can hit > 90db if I wanted to.

 

[Ken Boyd]

I have a number of his designs with the Cary, and the AES labels. Some I like better than others.

 

[BmWr75]

I was curious how loud 2 watts can get on an audio system. I know my guitar amp at 1watt can get super loud driving 2 twelves.

Dependent on speaker sensitivity.

 

[BmWr75]

100+db

Let say 100 then.

1 watt is 100 db
2 watt is 103 db
4 watt is 106 db and so on.

 

[x3workshop]

Here's my other Had amp. KT150's sound great @ about 10/11 watts.

 

[ceylon]

45 tubes are only available as old production or used best I can tell. Was not able to find any new production 45 tubes in a recent search.

i bet emission labs or another boutique manufacturer makes
em.

 

[ceylon]

1 watt would be plenty on my system.

could do parallel 1626–theyre still cheap from a legit retailer, of which there are fewer and fewer. there are proven schematics from all those darling builders