Bottlehead Forum

General Category => Technical topics => Topic started by: Giordano on December 29, 2022, 11:15:31 PM

Title: Crack -> Senn. HD560S
Post by: Giordano on December 29, 2022, 11:15:31 PM

Hello,
I made a search for 560S and went through a few output impedance threads, but still I would have a question:
I know the Chark handles the 300 Ohm of a HD800S fine, but how about a 120 Ohm of a HD560S?
Is Crack a good choice for the HD560S?
Thanks,
JG

Title: Re: Crack -> Senn. HD560S
Post by: Tom-s on December 30, 2022, 02:23:08 AM

It will probably work with Sound pressure level (SPL) 110 dB (1kHz, 1 Vrms) with the 6080.

You could opt to use a higher transconductance output tube like 5998 or 421A to lower the Cracks output impedance.

Title: Re: Crack -> Senn. HD560S
Post by: Giordano on December 30, 2022, 04:44:37 AM

I do not know what SPL I need. I thought  the base gets weak first. From one side, base is not the most important for me, but on the other side, it should have enough reserve. Anyone using a 120 Ohm headphone with the Crack? Thanks, JG

Title: Re: Crack -> Senn. HD560S
Post by: Doc B. on December 30, 2022, 05:34:56 AM

My hunch is it would work but it won't be optimal.

Title: Re: Crack -> Senn. HD560S
Post by: Paul Birkeland on December 30, 2022, 05:43:05 AM

The bass being weak can happen with really low impedance headphones and the coupling caps we use in the Crack, which are sized appropriately for the output impedance of the amplifier and the typical headphones it might drive. 

Regarding the output impedance of the amp, the further down you go in headphone impedance, the more exaggerated the bass and treble can get as the headphone impedance wiggles around at various frequencies.  For the 560S in particular, you will hear a 2.5 or so dB bass boost centered around 70Hz and nothing particularly worth noting up top.