Bottlehead Forum
Bottlehead Kits => Eros Phono => Topic started by: kip.duff on December 25, 2019, 04:24:14 PM
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I bought some nice German E80F Valvo NOS tubes for Eros 2 first stage. Based on some info in these treads, I believed they were compatible with E86F. But I did my voltage tests- got 1.7V at OkC and OkD with kit supplied tubes- within your recommended spec of 2.0V. With the Valvo tubes, I got 2.3V amd 2.5V. Is this a risk running these? Not an acceptable substitute?
Thanks, Kip.....
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I personally wouldn't use them. They use a bit more heater current, which isn't ideal for the 6.3V regulator. They will also have less gain and likely a little more noise than an EF86. The linearity of the EF86 with ~100V on the screen looks quite a bit better with 1.5V of bias than the EF80 with ~100V on the screen and 2.5V of bias.
Still, the Eros 2 will function as a phono preamp using them.
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Ya- didn't seem right. Glad I asked
Thanks for response- Kip.....
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I don't know why I wound up with these Valvo E80Fs. EF86s are affordable. All kinds of EFT, Telefunken, Valvo NOS or "test-NOS" offers on eBay. NOS matched pair of Bugle Boys or Mullard (Holland) under $100 pair on the high end.