E88c vs E88cc

[reinw33]

Hello guys,

was wondering about the difference of a Siemens E88c vs a Siemens E88CC for mic preamps from an operational quality difference point of view, so to speak, in general differences.

I can buy both, but the offered Siemens E88c from the Bundeswehr "German Army" with stamps on are significantly cheaper. Perhaps the E88c is tougher build quality?

Am currently looking into the E88c datasheet and about to download the E88CC datasheet to compare, but from an operational difference for mic preamps I have no experience.

Thank you!

 

[MagnetoSound]

The C stands for triode. One E88C is a single triode, E88CC has two.

 

[rock soderstrom]

The E88C only has one triode system, so the heater current is different. The pinout, gain, steepness and the intended use are also different, Anode current is similar.

Nevertheless, the E88C is a high quality tube and very interesting, but different and not interchangeable with the E88CC.

 

[Tubetec]

Ive used the E88C in a preamp I made and its a superb audio tube ,
Its doesnt have much in common with the dual triode ,
appart from the fact its high current, high gain ,
Its has the frame grid construction .

 

[reinw33]

The C stands for triode. One E88C is a single triode, E88CC has two.

The E88C only has one triode system, so the heater current is different. The pinout, gain, steepness and the intended use are also different, Anode current is similar.

Nevertheless, the E88C is a high quality tube and very interesting, but different and not interchangeable with the E88CC.

Yes, this clears up my question pretty much.
They differ quite fundamentally and significantly in their specs, thank you for the clarification.
I wasn't aware "C" means Triode, and it's jsut one with E88c.

Thinking about this for a moment.
Even though the single triode has twice the mu of the dual triode, I think it would not be a good idea to try to get away with using just one E88c doing twice the work.

All of this tube architecture is still a somewhat new field to me, but I can imagine having a brighter modern mic, a darker tube would go well with it?, or am I misleading myself here?
Like a darker 6DJ8/ECC88, instead of the higher resolution and quality E88CC.

 

[reinw33]

Ive used the E88C in a preamp I made and its a superb audio tube ,
Its doesnt have much in common with the dual triode ,
appart from the fact its high current, high gain ,
Its has the frame grid construction .

That's a nice wind of fresh air to hear, so to speak.
How many tubes of these E88c and tubes in total are in your designed amp?

 

[merlin]

I've never encountered an E88C in real life, but going by the datasheet it looks like a bloody good input valve, crazy specs for such a little boy!

I'm guessing microphonics would be the only thing likely to present an annoyance.

 

[rock soderstrom]

but going by the datasheet it looks like a bloody good input valve, crazy specs for such a little boy!

+1

I'm guessing microphonics would be the only thing likely to present an annoyance.

That was not that bad (frame grid tube), but a grid stopper is a good investment IMHO.

 

[merlin]

That was not that bad (frame grid tube)

Frame grids tend to be the most prone to microphonics

 

[rock soderstrom]

Frame grids tend to be the most prone to microphonics

Really, I always thought that was there to improve the microphonics behavior. Okay, but Telefunken's E88C was or is not particularly microphonic compared to a EF42, for example.

 

[nsalis]

"I've never encountered an E88C in real life..."

The E88C was typically used in antenna amplifiers, which were installed in the attic under the antenna mast.

Nick Salis

 

[reinw33]

I've never encountered an E88C in real life, but going by the datasheet it looks like a bloody good input valve, crazy specs for such a little boy!

I'm guessing microphonics would be the only thing likely to present an annoyance.

"I've never encountered an E88C in real life..."

The E88C was typically used in antenna amplifiers, which were installed in the attic under the antenna mast.

Nick Salis

Right, they mention in the datasheet that it's for RF UHF transmission, it depends on convention, like Mhz 315-915.
The HAM band is 150Mhz-174Mhz, so it's not ment for that HAM frequency. I guess that's why so few went to the US?

In terms of microphonics, can't those be filtered out somehow?, like with decoupling or shielding?
I wonder how it would perform compared to one half of a 12ax7 and a 5751, that I actually own, as mic stage, but I haven't tried neither one out for that matter, yet.
How bad there aren't any microphonics tests to compare, aren't here?

 

[Tubetec]

The preamp I made uses a single E88c ,
It uses an anode load resistor of 6.8k , cap coupled to the transformer ,
I incorporated variable feedback as gain control and a single NIMH cell to provide cathode bias , the NIMH cell on charge with the cathode current of the tube running through it keeps a very stable 1.25v difference between grid and cathode .
I did go to the extra trouble of anti vibration mounting the tube on this pre , but in general the E88C has very good performance with regards microphonics ,self noise is also extremely low , bandwidth with a 6.8k ohm anode load is huge .
The nice thing about feedback over a single wide band stage is there was no tendency to oscillate even with the entire gain reduced to around unity ,
I remember posting a mostly complete schematic around here somewhere ,
but I dont have a copy to hand just now .
The design had one shortcoming , input and output impedence varied a bit depending on the FB level , it worked best with a particular step up to grid transformer I have , enough gain without feedback for dynamic mics on lower level sources and with FB adjusted to suit using condenser mics. Balanced line sources can also be used via a suitable transformer ,

 

[Tubetec]

Even though I have the unit on the shelf beside me its been a few years since I powered it up ,
I must have a proper look with REW again ,
Downside of a battery grid or cathode battery supply is it needs maintenance if the unit remains unused for a time ,leakage is also a factor with certain battery chemistries .

 

[Tubetec]

https://groupdiy.com/threads/e88c-preamp-comments-critisisms-required.66208/

 

[Chandra]

What I could recall from memory,
ExxCC are for Industrial application with 10,000 hours filament life,
ECCxx are for standard radio application with 1000 hours filament life.
We used to buy Philips E83CC for our factory during those days in the 1980s
Regards.

 

[gyraf]

Yes EC88 /E88C is quite different from ECC88 and E88CC (which are actually not the same, but two different tubes, look at cathode/heater voltage specs etc)

EC88 has higher gain, tolerates higher voltages, and is significantly more hysteric when it comes to oscillation. And oh, it's dirt-cheap and plentiful.

I've recently tried it in a eq setup (reviving the G6 project that was lost to time) and it behaved really well audio-wise with decently-sized grid-stoppers in place (470 Ohm iirc)

Definitely worth trying out for audio duties, but not at all ½ECC88

/Jakob E.