I lay may hands on a very good amount of some quality tubes
EF184 made by EDICRON
ECH 84 made by RCA
PCF 802 made by pHILIPS
Can any one suggest audio circuits that operate good with these tubes ?
EF184 made by EDICRON
ECH 84 made by RCA
PCF 802 made by pHILIPS
Can any one suggest audio circuits that operate good with these tubes ?
EF184 makes good phono tubes or driver tubes for power amp, or parafeed preamp output. The others I don't know, means irrelevant in audio.
As far as I know these are TV tubes with limited audio use. The EF184 could be used in a preamp or the first stages of an amp, in pentode or triode. It's a good tube in triode. In an amp it would be followed by a bigger tube with more currant. Not a useful driver in itself unless you use a cathode/source follower. Maybe you have some other tubes or just these three types?
PCF 802: Almost identical pentode with E/PCF 80, high µ triode similar to a 6SL7 half. So, why not?
Best regards!
Best regards!
be nice to me ...i am only a bipolar transistor person
anyone has a link to a schematic ? just to get an idea ?
anyone has a link to a schematic ? just to get an idea ?
Mixed sets of E and P tubes were very common in those days! ECC 81, ECC 82, EF 80, EF 85 and the aformentioned ECH 84 and EF 184 (and some more) lived happily next to PL 81's, PL 36's, PL 504's etc.
Best regards!
Best regards!
ef184 will du fine in riaa
pcf802 is similar to 7199 / 6u8 / ecf82 with a different filament voltage ( 9 volt). Could be used as amplifier/phase inverter a la dynaco MkIII
Hi andy you wrote about EF184 in triode connection
'Not a useful driver in itself unless you use a cathode/source follower.'
My 300B se class A output stage is driven by choke loaded EF184, 180volt at plate 2.5volt at cathode, 10ma cathode current cap coupled to 300B grid and it gives me wonderful sound. In this config u is more than 50 and internal plate resistance is about 3k. Please note I also have used E810F and E180F to drive the same output stage. All three are very nice 300b driver.
Regards
'Not a useful driver in itself unless you use a cathode/source follower.'
My 300B se class A output stage is driven by choke loaded EF184, 180volt at plate 2.5volt at cathode, 10ma cathode current cap coupled to 300B grid and it gives me wonderful sound. In this config u is more than 50 and internal plate resistance is about 3k. Please note I also have used E810F and E180F to drive the same output stage. All three are very nice 300b driver.
Regards
I agree. As a triode EF184 has gm > 16 mA/V and therefore low Rp. So it has more capacity than any 12A...7 types as well as 6DJ8, 6N6P etc.
Yes, as I said in #4. Though it has been dedicatedly designed for sweep oscillator service in TV's, the PCF802 isn't a bad audio tube at all.
Best regards!
Best regards!
I've never come to see a mixed heater set of tubes in gear, not one in more than four decades.
Please let us all know, where they have been used.
I mean, tell us, which gear (manufacturer and model number) they have been employed.
If they were so common, as you said, why did it make sense?
They use different PSU and the P- tubes, we all know, were used in TV sets and not in audio amps. And thats for some reason.
So why should they mix them up?
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I don't see a problem with mixing EL and PL. Start with a main 6v supply for the EL tubes and add a small booster 12v supply if for instance your PL is 18v. Not much of an issue. PL tubes are usually cheaper.
I'm not talking about DIY and the today prices.
I'm talking about the times, when this kind of tubes were used in all kind of commercial gear.
And with that, it makes absolute no sense to use E- and P- heater tubes in one set of tubes.
Either you design a for a set of P- heater tubes or you design the gear for a set of E- heater tubes.
For you, it may differ only in some euros to use both.
In a series production with some hundred thousand pieces, nobody does that for no reason. Even when it only cost some cents more.
And I don't see that P- tubes were generally cheaper those days.
I'm talking about the times, when this kind of tubes were used in all kind of commercial gear.
And with that, it makes absolute no sense to use E- and P- heater tubes in one set of tubes.
Either you design a for a set of P- heater tubes or you design the gear for a set of E- heater tubes.
For you, it may differ only in some euros to use both.
In a series production with some hundred thousand pieces, nobody does that for no reason. Even when it only cost some cents more.
And I don't see that P- tubes were generally cheaper those days.
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Yes - makes sense in commercial gear of course. PL tubes may or may not be cheaper but in some cases they're easier to buy on eBay.
There were umpzillions of different European TV sets from the 1950ies to the early 1970ies that had P and E tubes next to each other.
Best regards!
Best regards!
I've already wrote, that I'm not talking ebay or DIY.
There was no ebay in 1960s and even if, it were irrelevant for the commercial companies. They have and still buy electronics wholesale.
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OK, your rigth. Found some old schemos and they use mixed types. For whatever reason they did.
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It's nothing strange here, ECC81/82/83 draws 300mA and is thus usable in a P-series filament string. In fact there was never any PCC83
At the same time PCC88 is usable with 6.3V filament.