[Tax]

Can any current or previous NoH TVC owners provide me with some advice with regards to tube and SS phonostages?

I am considering the addition of a phonostage and am undecided on whether it should be SS or Tubed.

Are there any known issues with impedance matching of tube phonos?

My amps are PP 300B's and they work fine with the NoH. My cables are no longer than 2M's. My NoH is unbalanced.

Thanks
Tax

[John Chapman]

Hello!

I tend to favor tubes myself - not that it is particular to the NOH really. More just a personal preference. I am using a PP 300B myself much of the time and sometimes a SE2A3 or 45 depending on speakers.

The only thing to watch out for with a tube phono stage is very high output impedances - like over 1K or so. Two phono stages I have used (and loved) are the K&K stage and the Haggerman Trumpet. Both really great products and really nice guys.

Also had a bit of time with a stage made by Anatek Acoustics in the UK. It was a really nice SS phono stage that could run an MC cart direct (so good value as a package) but I only had it here for a short time (it went on to a distributer in Canada for eval) so I can't really make a detailed comparison.  I think they may have changed company names a while back - need to get up to date on that.


Thansk!

John

[Tax]

Thanks John.

I am thinking of a Klyne 7PX, have you or any other owners of the NoH had any experience with the Klyne?

Also under consideration is a Herron VTPH-2 (tube) and Vitus battery powered RP-100.

Kind regards
Tax

[Mondie]

l run an EAR 834 with my TAP and it sounds superb, no issues here

Cheers Mondie

[John Chapman]

Hello!

I should have mentioned the 834 - it is really decent and they show up often in the used market. Lots out there!

Thansk!

John

[mingles]

The EAR 834P has an output impedance of ~525 ohms and sounds nice running through John's TVC. I also had George Wright's WPP100C and WPP200C running though the TVC. They both have an output impedance of 2k ohms, yet they sound spectacular. IMO, they were better than the 834P in terms of tonal accuracy and in creating a sense of spaciousness. I often wondered whether I was missing something due to their high impedance, but Jonathan Dunham's tech notes for the TX-102 says:

"At the highest source impedance point the bandwidth may be somewhat compromised and distortion will rise. For the unity gain connection the sensible upper limit of impedance is around 5kOhm, this causing a -1db point of 20Hz. If more attenuation at very low frequencies is allowable (or indeed desired) however, a source impedance of around 15kOhm will result in a -2.7db roll off at 20Hz."

http://www.stevens-billington.co.uk/page102.htm

This confirmed what my ears already knew... that a 2k ohm source impedance wasn't a problem for the S&B trannies. My ICs were 1m Kimber Hero's.

John, I'm curious how your new autoformer-based preamp will handle source impedance. Will it be similar to the S&B's?

[John Chapman]

Hello!

When it comes to source impedance there are several factors at work all at once. The '1K rule' was a guideline to simplify things and since it is quite rare to have an imp over 1K it was an easy target to work with. Other factors that come into play are the range of taps you use - ie. are you normally right up near the top of the volume levels or down in the middle or lower.  Also the amp load to be driven in the end. Because of this there are no specific 'go-no go' number.  I am using the same basic range for the new unit - although it also does include the "SYB' buffer. The new pre-amp has a separate signal path for the sub output and as a result it was easy to insert a buffer inline (optional via remote handset) for any given input. The 'Save Your Butt' buffer is there in case a source has any trouble in your particular situation. I won't be surprised at all if no user ever finds a need to use it but it felt good to include it anyway.

Thansk!

John

[Tax]

I ended up going with a Klyne 7PX 3.5 phonostage and it works fine with the Bent NoH.