Passive Creek pre-amp with Quad 303 power?

[admin_exported]

Hi,

I have been using my quad 33 pre with a refurbished 303 power amp based system along with my cyrus cd8x, but feel I can get some improvements on the 33. I've been thinking seriously about the Creek passive pre-amp, the OBH-22, which doesn't just have the attraction of simple electronics, but also is quite affordable. My question is whether anyone has tried similar combinations, and whether in theory this combination should work.

The cyrus output is 2.1V RMS and a 50 Ohm output impedence

The creek pre has input of >20 kOhms and output of 0 to 20 kOhms

The quad 303 original specs are as here:

http://www.retrohifi.co.uk/quad_303.html

Will this work in theory? Any suggestions?

Cheers,

Jamie

 

[lordmortlock]

Hi Jamie

Should be fine - I use a 909 with a Rothwell passive and I love the sound. Keep those interconnects nice and short mind... no more than a metre and shorter if possible.

 

[Anonymous]

You can always use Rothwell attenuators between pre and power if the gain is still too high. If you want the next level up from the Creek then look for a passive pre that uses a stepped attenuator for the volume control like this Netaudio one.

 

[lordmortlock]

Theres been a few passives sold on the bay recently too - An audio thrills piece went for beer money. Theres a couple of Creeks on there now.

EDIT - keep an eye on this too

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=120474907713&ssPageName=STRK:MEWAX:IT#ht_600wt_930

 

[Anonymous]

Lord, what's the score on the LFDs?

 

[a91gti]

When I had a 303 some years ago I just connected my cdp straight to it. Great sound, you'd need a variable out equipped cdp tho and I don't know if the cyrus has this.

 

[lordmortlock]

igglebert:Lord, what's the score on the LFDs?

Bit of a weird one that - basically I had a good listen and just couldn't get with the sound. The tops were really harsh - so much that it prompted me to think something was wrong. I sat down to listen again and something popped on the left block - thought I'd blown my ATCs up!

I called Mark at Audio Emotion (fantastic as always) and they collected them. Apparently a fuse had gone. Thats been replaced and Mark had someone else who wanted them. The whole situation left me a bit cold so I've had a refund and they've been resold. Both Mark and the new buyer have re listened and think it sounds wonderful so either I have cloth ears or there was a problem pre 'pop' and the amps weren't sounding at their best.

Its a shame. I really feel like I've missed out on something wonderful but something wasn't right - found the sound uninvolving... almost cold. I'd love to have a listen to another set. Perhaps they just aren't to my taste?

 

[Anonymous]

That's really interesting. As I'm sure you know, fuses blow for a reason and simply swapping them out isn't always very wise. My Quad amp had an issue and it kept destroying the transistors! It came back to a loose resistor.

Put it down to fate and just buy a second Quad 909 for mono

 

[lordmortlock]

Ha I was thinking along those lines! I'm curious as to how much better a sound I'd get from two 909s - its not as if just the one on its owns suffers from a lack of power. What improvements would you expect?

I guess I'm not too bothered about them going back. Its nailed home that 'good sound' is very much a matter of preference. I was also going to have to pay top £££ for the lfd linestage as Mark didn't want to split and I'm not sure I'll ever move away from passive pre amps now.

 

[Anonymous]

Well another 909 would give you a lot more current so I'd expect a degree of improved drive unit control. This would probably give you tighter bass and make it possibly sound a bit leaner. As to how much difference it would make I don't know.

 

[Anonymous]

Cheers everyone for the advice and suggestions.

1) I hadn't quite twigged it was a motorized pot rather than a stepped attenuator. Does a passive pre exist with a motorized stepped att. in it? I guess not, or if it does for extortionate money? I liked the idea of a remote control circuit that turns itself off when not in use, and staying out the signal path. Having a wife who is often complaining about the volume means alot of getting up and down; volume down, wife out, door closed volume back up etc. that, and the fact i'm something of a lazy git.

2) Regarding interconnects, any recommendations of makes, and ones that are available in short lengths, i'd rather not have to resolder things, though I can if its the way forward. Also, which is more important to keep short, the source to pre, or the pre to power, or both.

Thanks,

Jamie

 

[lordmortlock]

Hi Jamie

Yeah most passives have manual control only due to the lack of powered parts. The very very top of the range music first has a remote and they've done it by a motorised control on the volume knob only so as to not interfere with the passive workings. Hopefully its made of gold and diamonds given that the unit costs about £8k!!

Have you considered making your own passive pre? Its about as straight forward as home built hifi gets. I'm going to give it a go. Theres a kit available from an international ebay seller and check the last post on this thread - v. interesting

http://community.whathifi.com/forums/t/305592.aspx

I wouldn't worry about re soldering if interconnects are a metre - perceived wisdom is that this is a fine length. I think both in and out are important as you are essentially using the current output from the cdp/source so it probably needs to pass through to the amp at a sufficient level.

If you have to re buy then maybe chord chameleon or some silver hi breed from ebay. I use chunky cable from the bay. Warning - Cable discussions can get a bit heated on here!

 

[Anonymous]

Spot on Lordmortlock.

The Netaudio passive pre I linked above is pretty cheap and has a stepped attenuator instead of POT.

 

[Anonymous]

Thought I should post this under the old thread rather than create a new one.

After your advice, I decided I'd prefer to go for a stepped attenuator based preamp rather than a motorised pot. I'm seriously thinking of tackling making my own preamp. However, I haven't been able to work out what max resistance would be right because I only have the old quad 303 values to work with (see top of thread). In the end, and given that folk thought the Creek, which has a maximum of 20KOhm, would work well with my Cyrus and the Quad 303, I decided I could simulate a passive pre, by using an in-line attenuator between cd and power amp. I thought it would be sensible to go for a bigger resistance first just in case, and went for 20kOhm (as per the max of the creek passive) and soldered these resistors into the RCA ends of some old IXOS cables I had.

First off. I put on the four last songs, Felicite Lott, my favourite recording, the clarity and openness was immediate and stunning, as was the characerisation of her voice, which with the quad 33 pre can sometimes have an occasional edge. The brash edge on her voice was gone, and the dynamic range was also enhanced. Infact, while it was quite loud from the off, it wasn't ever harshly loud, that is, until I got the climax, and a heap of distortion appeared, and my wife ran in asking why I was trying to wake the baby up upstairs (not mine, the flat above). I guess, with the more open sound, it didn't strike me as loud as it might otherwise? While I now know I like not having my quad 33 in the signal chain, clearly, 20kOhms isn't enough.

Am I right in saying that a single value in-line attenuator of an appropriate resistance is a simulator of a passive pre at a particular indexed volume position? In which case, how do I know what stepped attenuator in my passive is going to be appropriate?

 

[Anonymous]

You're certainly right in your last statement, a stepped attenuator pre is just a set of different resistors to switch between. Can't help you with the maths bit though! I'm lazy so would use trial and error.