Valve Itch phono

[merlin el mago]

Felipe, I use this MODULE LAMPEMETRE ANALYSEUR - VACUUM TUBE ANALYZER | eBay

Cheers

Gracies company. Thank you.

Bona nit. Good night.

Felip

 

[merlin el mago]

Hi,

@Merlin el Mago:

Should you go through with the E2833CC mod know that these are as close to the famous TFK ECC803S as you can get.
Less distortion, lower noise, no microphony I can remember, frame grid construction and so on. But like most low distortion valves, not to everyone's liking.

Cheers, 😉

Hi Frank,

I bought several years ago to Erno Borbely & paid a lot of money for each tube. The 6n2p-ev are sounding glorius and if memory don't falls Itch was a little bit complicated the heaters connections.

Greetings
Felipe

 

[fdegrove]

Hi,

Sure, if I were asked to design a phono preamp today I'd go for the 6N2P-Ev too.

I currently use it to drive a pair of 2A3s in an amp.

Back in the early nineties I used E283CCs as error amps in voltage regs and ECC808s, C3As and E80CCs in an MC/MM phono preamp too.
Gone are the days....

Just saying these E283CCs are not just your regular run off the mill valve, they're masterpieces of technology.

Cherish them , 😉

 

[merlin el mago]

Hi,

I always trusted Erno Borbely advice, you are right can be 15 years or more I bought the tubes, I know are little gems because I checked the prices and are high.

Thanks for your advice Frank🙂

Felipe

 

[merlin el mago]

Salas before changing for E283CC I want to check in the real schematic if the E283CC tubes are good, attached schematic.

TIA
Felipe

 

[merlin el mago]

It nice in the small suitcase. Do they sell that "Duo Vac" front plate that screws in the suitcase separately?

Alain ask for DuoVac ( tester ready to use in flight-case) is 380 euros + 25 euros shipping.

Attached french manual.

 

[Salas]

Salas before changing for E283CC I want to check in the real schematic if the E283CC tubes are good, attached schematic.

TIA
Felipe

I don't have model for that tube Felipe but it should be biasing fairly normally there because 6N2, 12AX7, E283CC are very near electrically.

 

[merlin el mago]

Can I use the schematic posted? Where have to measure and what are the right mesurements?

 

[Salas]

Yes you can. 285V at the top anode, 180V at the bottom anode, 56V across the 82K. All those are rough estimates.

 

[merlin el mago]

I measured E283CC cathodes pins 1 & 6 to center tap heater pin 7 and is open circuit so looks good, also I measured heaters 4 to 5 and measures both tubes 3 ohm, is right? I ask because I have other 12AX7 brands:

JJ 10R5 I have only 1 tube
Groove tubes 9R5-10R
Sovtek 17-18R
6N2P-EV 7R-8R rocket logo
Sovtek HQ 32R-34R
RSD 12R5-13R5

 

[merlin el mago]

Yes you can. 285V at the top anode, 180V at the bottom anode, 56V across the 82K. All those are rough estimates.

Thanks Salas.

What do you think about the heaters low ohmic value of the Siemens E283CC?

 

[Salas]

That's cold value and its down to chemistry specials. Just check if they draw around 330mA as the spec is when lightening them up with the bench PSU.

 

[merlin el mago]

One 317mA the other 324mA.

 

[merlin el mago]

Attached measurements.

 

[Salas]

Siemens states 313-347mA heater current in its manual so the tubes are good. The current in the stage looks normal like 0.63-0.80mA. Try with IR Led too instead of 2Xdiode to see if the bottom readings will match voltages better.

 

[merlin el mago]

The same IR Led of 2V or less as used in the BiB?

 

[Salas]

Infrared invisible light to the eye Led like those in remote controls about 1.2V Vf

 

[merlin el mago]

Ok I will call tomorrow to the local electronic shop to know if they have.

 

[merlin el mago]

Salas I found this IR Led in the local shop tsop1333 (attached data sheet), is OK? I don't find Vf parameter btw what's Vf?

 

[Salas]

Voltage drop of it when conducting is Vf. IR Leds have low about 1.2V. What you found is an infrared receiver system. Don't they have simple IR emitter Led? Crack an old remote control and take one out 🙂