Advice on Passive Pre-amp

[ovlov854]

Hi all. I thought I would try a passive pre as my TT does not get any use.
Totally puzzled on how I determine the log value needed
Any ideas??:scratch:

[Firebottle]

SS amps generally have lower input impedances, perhaps 22K or 10K on some.

Valve amps generally have higher input impedances, perhaps 100K or even going as high as 1M.

I usually opt for something in the middle that will work with either, so 50K for me.

[ovlov854]

Thanks Alan, the Sirius is 10k so it should be OK

[hifinutt]

I have the marvellous freya passive which seems excellent. Be happy to pop round one day and try in your system

[ovlov854]

I have the marvellous freya passive which seems excellent. Be happy to pop round one day and try in your system

That sounds like a good idea. I have a Khozmo arriving at some time???? so would be ideal then

[hifinutt]

Excellent , nearly got a khozmo recently but not enough inputs . The freya has loads and several for too. Let me know when arrives and we can compare

[Pepperamip]

Excellent , nearly got a khozmo recently but not enough inputs . The freya has loads and several for too. Let me know when arrives and we can compare

Phil, I'm having a BTE Designs preamp made up with a Khozmo stepped attenuator and you can have as many inputs and outputs as you wish.

[DSJR]

Please note that when passives work well, they're transparent to the source as long as the source output impedance is low and the amp input impedance fairly high, but some power amps don't like them and response errors and HUM can become an issue. Fancy attenuators tend to look and feel nice, but I'd check with a standard film pot first before shelling out hundreds on a posh Khozmo. It's not quite as cut-n-dried as it would seem and the pot value can make a difference to either source or the amp it's used with.

[Pepperamip]

Hi David, so if enjoyed the sound of my Tisbury Passive much more than a recent active tube preamp I acquired and quickly moved on I might not necessarily enjoy the sound from my new BTE preamp? I've given Mr Cresswell details of my source and power amp equipment and he seemed to think it would work nicely. I must say I will be mightily disappointed if it doesn't at least match the Tizzy. My guess is that it will or at least I hope it will.

[hifinutt]

Thanks for those salient bits of advice . Not had passive amps for some years while using modwright. However rather attracted by the freya as has valve and passive options . There is not huge differences but the passive is deadly silent and valve stage occassionaly gives a small bit of hiss or noise depending on which system I am using it in

[ovlov854]

Well the Khozmo has arrived and been installed.
Not too sure how best to operate it with my HPA which has its own volume pot.
First set the HPA pot to half way and then adjusted Khozmo to suit. More detail than before but some strange faint indiscernible noises.
The HPA is a battery powered valve amp using a 5751 valve and is very quiet.
Then tried with the HPA pot wide open and the Khozmo pot to suit......better but does running the HPA at full volume shorten its life or valve life???

[struth]

leaving it full on is closest way to not having it there so sound should be better.

[walpurgis]

Why would you want to add a passive pre-amp if your main amp has a volume control anyway?

[Firebottle]

Crap volume control in pre?

[Macca]

Crap volume control in pre?

You're still running the signal through it though. Better to disconnect it entirely I'd have thought?

[flapland]

Martin, responded to your PM over on PFM. As others have suggested I would try the Khozmo direct first and see if you still get the issues reported.

[ovlov854]

Why would you want to add a passive pre-amp if your main amp has a volume control anyway?


Crap volume control in pre?


You're still running the signal through it though. Better to disconnect it entirely I'd have thought?


Martin, responded to your PM over on PFM. As others have suggested I would try the Khozmo direct first and see if you still get the issues reported.
Thanks for the responses guys.
I'm not running the Khozmo together with my pre which is a Hovland with a pretty sophisticated attenuator but instead of it.
I am toying with the idea of forsaking the LP12 and the Hovland with its fabulous MC phono stage and have bought the Khozmo to evaluate, and perhaps getting a Hattor and a more modest TT
So far the level of detail with the HPA wide open is considerable