Eros tape head output impedance

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Offline [email protected]

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on: August 07, 2024, 01:33:47 PM
Can you inform me as to the output impedance for the eros tape head and is there a way that I can modify it to do double duty for phono or tape.

Thanks
Donald

Don Troise


Offline Paul Joppa

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Reply #1 on: August 07, 2024, 03:28:39 PM
[Note that the tape head version was discontinued a few years ago. We now offer only the RIAA version.]

The output impedance is around 4K-5K ohms IIRC.

While it is theoretically possible to make a switched set of different equalization networks, it is pretty complicated, and we never designed one. One would have to re-design the networks, and then find a place to locate the extra components and the switch. The area is pretty cramped, and the circuitry is sensitive to interfefence (hum and oscillation risk).

We did at one time make a tape-only version with a NAB/IEC switch, which changes only the LF time constant and is much simpler. It was something of a kludge and was abandoned about a decade ago.

Paul Joppa


Offline [email protected]

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Reply #2 on: August 08, 2024, 04:33:46 AM
Thanks for the response, Paul

I own an Eros tape head and I am changing my system to a passive pre-amp with 600 ohm 1:1 transformers for multiple outputs for a multi-amp system, the output impedance of the Eros is quite high, is there a way to change it to 600 ohms or do I have to use a buffer.
BTW this is the quietest tube equipment I have ever heard, at full volume w/o signal there is zero increase in the normal noise floor and my system has compression horns at 116 db.

Thanks

Don Troise


Offline Paul Joppa

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Reply #3 on: August 08, 2024, 05:28:38 AM
In the Repro, we had a third stage of amplification, loaded by a 15K:600 ohm output transformer, to get pro-level low impedance outputs.

Paul Joppa


Offline Paul Birkeland

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Reply #4 on: August 11, 2024, 06:01:24 AM
I am changing my system to a passive pre-amp with 600 ohm 1:1 transformers for multiple outputs for a multi-amp system
Why?  That seems like a bit of an odd choice for HiFi.

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man