SpeakerTalk Forum Index SpeakerTalk
This forum has been set up to facilitate discussion of 1970s KEF speakers and drive units. The owner of the Forum has no connection with KEF Audio.
 
 FAQFAQ   SearchSearch   MemberlistMemberlist   UsergroupsUsergroups   RegisterRegister 
 ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in 

Advice on VSI60 Integrated Amp for KEF Speakers

 
Post new topic   Reply to topic    SpeakerTalk Forum Index -> Audio equipment
View previous topic :: View next topic  
Author Message
skyhawk
Introductory Contributor


Joined: 21 May 2013
Posts: 5

PostPosted: Sun May 26, 2013 11:23 pm    Post subject: Advice on VSI60 Integrated Amp for KEF Speakers Reply with quote

Hello everyone. Question, would the Audio Research VSI60 integrated amp be a good choice to match up with the KEF 104ab speakers?
2nd question, does the VSI60 amp have a passive pre-amp inside it?
Thanks to all who respond.
Back to top
View user's profile Send private message
TL 200
Senior Contributor 100+


Joined: 27 Jul 2009
Posts: 141
Location: Emmer-Compascuum The Netherlands

PostPosted: Mon May 27, 2013 10:32 am    Post subject: Re: Advice on VSI60 Integrated Amp for KEF Speakers Reply with quote

skyhawk wrote:
Hello everyone. Question, would the Audio Research VSI60 integrated amp be a good choice to match up with the KEF 104ab speakers?
2nd question, does the VSI60 amp have a passive pre-amp inside it?
Thanks to all who respond.


http://www.audioresearch.com/VSi60.html
Take a look at this.
_________________
Without music, life would be a mistake.

Friedrich Wilhelm Nietzsche,
The Twilight of the Idols, 1889
Back to top
View user's profile Send private message
skyhawk
Introductory Contributor


Joined: 21 May 2013
Posts: 5

PostPosted: Tue May 28, 2013 2:12 am    Post subject: Reply with quote

I see. So the VSI60 has a passive preamp. What would be the result of using it with the KEF ab speakers? I don't understand why a passive preamp would not be a good match for the KEFs.
Back to top
View user's profile Send private message
audiolabtower
VIP Contributor 500+


Joined: 06 Jan 2009
Posts: 544

PostPosted: Tue May 28, 2013 10:20 am    Post subject: Reply with quote

There is no reason a passive preamp should not be ok. It is basically just a potentiometer on the input of the power amp, as long as the amp has sufficient sensitivity for whatever inputs you use the speakers can be driven to capacity. In the vs160 is appears to be relay controlled resistor ladder? The 50 watts is rated at 1.5% distortion which means that the usual way of defining power at 0.1% distortion is going to be somewhat less power. Purely my personal opinion I would like nearer a 100W amp with the 104s for transients since they are probably one of the most inefficient speakers Kef made. However valve amps are forgiving of clipping and depending on the size of your room and the loudness required it might be fine. But the vs160 talks about low impedance drive, the 104 is more like 10 ohms minimum across the power hungry bass and midrange, whether it has the voltage drive to run the 104s to capacity might be debatable?
Back to top
View user's profile Send private message
skyhawk
Introductory Contributor


Joined: 21 May 2013
Posts: 5

PostPosted: Tue May 28, 2013 10:44 am    Post subject: Reply with quote

Thanks for the reply. I had been considering the Jolida 302CRC integrated amp. Then I saw and read about the VSI 60 amp. I really want a tube amp. Any thoughts on the Jolida amp? I really don't want to buy something used unless I really know the history of the component. Any suggestions?
Back to top
View user's profile Send private message
iso
Senior Contributor 200+


Joined: 29 Aug 2011
Posts: 215
Location: Finland

PostPosted: Wed May 29, 2013 12:27 am    Post subject: VSI60 Reply with quote

Vsi60 specs specify 7dB or was it 7,5dB overal feedback... so outputimpedance would be something like 1,5-2,5 ohm from 8 ohm tap. Audiolabtower might have better undestanding how much 104aB do have impedanse variation... but I suppose that this is not ideal situation.

ARC Classics and CJ Premier 11 do have outputimpedances at around 0,5ohm, so speaker load caracteristics are not too important consideration with them. But they do need proper preamp for good performance.

Audiolabtowers note about unbuffered pot in integrated amp like VSI60 is correct. Situation is bit different when using poweramps due inteconnects and maybe for other reasons too.

Best Regards

Kimmo
Back to top
View user's profile Send private message
audiolabtower
VIP Contributor 500+


Joined: 06 Jan 2009
Posts: 544

PostPosted: Wed May 29, 2013 3:03 pm    Post subject: Re: VSI60 Reply with quote

iso wrote:
Audiolabtower might have better undestanding how much 104aB do have impedanse variation...
Kimmo


My old 104 manual showed 10 ohm to ~ 40 to 60 ohm (depending on switch position) up to 5 kHz, and 6 ohm at 10 kHz so you are quite right, a high amp output impedance will give a freq response that is a squashed down curve of the impedance plot. One of the reasons amps can sound different if the energy outputs in different frequency bands differ from flat to "lumpy" giving the impression of more or less detail etc.
Back to top
View user's profile Send private message
Display posts from previous:   
Post new topic   Reply to topic    SpeakerTalk Forum Index -> Audio equipment All times are GMT + 1 Hour
Page 1 of 1

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum


Powered by phpBB © 2001, 2005 phpBB Group