Pre-amp recommendation please

[Idlewithnodrive]

OK, I'm not sure that such a thing even exists, but here we go anyway.

I really like my Quad 34 pre (with mm phono card), mainly because of the wonderful tone controls. The thing I don't get on with is the stepped attenuator volume control. I am very sensitive to volume and quite often adjust volume track to track, considering ambient conditions etc.

It wasn't a problem when my old power amp had a pot volume control, but my new one doesn't, and so I rely on the stepped attenuator of the Quad.

And don't you just know it, the ideal volume is always between two steps !!

So, my question to you learned gents is, do you know of any Quad like pre-amps, with mm phono, continuous volume control and decent tone controls in the £ 2 - 300 mark ?

Be interested to hear your thoughts / suggestions.

Thanks.

[Jazid]

Add a passive or a Pass buffer with volume control after the pre for finer control? Or if you use digital sources use digi volume control. There's nothing quite like the Quad pre's that I'm aware of and the style is unique so...

Sent from my BLA-L09 using Tapatalk

[hifinutt]

I sympathise with you , one main reason I use my bel can to pre 3 is it has 200 volume steps,remembers the vol of each input and costs just 600 sh .big shame it does not have tone controls though

[walpurgis]

The Audiolab 8000C and NAD 1020 are not that dissimilar to the Quad 34 in presentation and have the features you want.

[Idlewithnodrive]

I did think of doing that James but another box and another set of cables ? They could degrade the sound, surely ?

[Idlewithnodrive]

Thanks Geoff. I'll look into those.

Does anybody know if it is possible to change the stepped attenuator for a pot in the Quad 34 ?

[mikmas]

Does anybody know if it is possible to change the stepped attenuator for a pot in the Quad 34 ?

Just had a look in my 34 to refresh my memory and indeed the attenuator is noticeably larger than most standard pots so you would encounter problems lining up the shaft with the front plate. Complicated further by the balance control mechanism which relies on a collar that the attenuator shaft runs through (as pivot and anchor).

Obviously If you can find a pot with matching casing dimensions that would makes things easier. Can't check the pin spacing without too much dismantling but your first obstacle would be the symmetry/match I would think.

[mikmas]

Does anybody know if it is possible to change the stepped attenuator for a pot in the Quad 34 ?

Just another thought on this - in terms of mechanics; as a standard pot is smaller it should be possible to mount it with the pins facing upwards (or sideways) and run wires from the PCB to connect. This is provided you can mount it to the inner chassis OK and run the shaft though the balance control mechanism. Whether it would present a problem electronically I have no idea, I think the attentuator is nominally 50k but don't know whether a 50k pot would provide a match ... I'm sure someone much more qualified can confirm ;)

[Firebottle]

Shouldn't be a problem to change the pot I think, from memory the original is quite large as stated above. Fitting the same resistance won't affect the sound.

I have a feeling that the original isn't a stepped attenuator at all, just that there is an indent mechanism built into the pot. I wonder if that can be defeated to give continuous rotation.
I will gladly look at it for you if you wish.

[Firebottle]

I have the circuit diagram at home, I'll check it when I get back later.

[Idlewithnodrive]

Shouldn't be a problem to change the pot I think, from memory the original is quite large as stated above. Fitting the same resistance won't affect the sound.

I have a feeling that the original isn't a stepped attenuator at all, just that there is an indent mechanism built into the pot. I wonder if that can be defeated to give continuous rotation.
I will gladly look at it for you if you wish.

If you think the stepped attenuator could be replaced / defeated, I would be happy for you to take a look Alan :) Thanks.

[Firebottle]

I have checked the circuit diagram and the volume control is an active stage, so I'm convinced the 'step' positions are built into the vol pot mechanism.

However you can't just replace the pot with a standard one as the 'law' of the pot, that is the degree of change of resistance per rotational turn isn't standard.
The pot is specially made for Quad with a special law to suit the active volume stage.

If anything can be done it would have to be a mechanical modification to the fitted volume control.

[Idlewithnodrive]

Do you reckon it is doable mechanically ? ie removing the indented ring (I assume) that retains the ball bearings (?) to imitate steps.

[Firebottle]

I would think so, they have to be assembled originally so dis-assembly should be possible.

[DSJR]

I was never a fan of the 34 myself, preferring the 44 in all its versions as I thought the sound clearer...

The 66 and 77 were rather better again I thought, offering clearer reproduction of recording venue and greater dynamic contrasts on rock and jazz material. The 77 had a flaky remote system and this all but killed the original company I gather, but of you can find a clean one, you may love it as I do. The 99 was similar I gather but these were sold as systems so may not come up alone.

[DSJR]

P.S. The output gain on the 34 was adjustable, so it may be possible to customise it that way?

[walpurgis]

I was never a fan of the 34 myself, preferring the 44 in all its versions as I thought the sound clearer...

I thought so too. The 34 has a sound that will never offend, but I just didn't find it very exciting.

[Idlewithnodrive]

Looking for Quad 66 or 77 pre's reveals none for sale, unfortunately.

[Idlewithnodrive]

I would think so, they have to be assembled originally so dis-assembly should be possible.

Would you be happy to take a look, should I go down that route, Alan ?

[Firebottle]

Yes no problem.

[337alant]

As Far as I know its not a stepped attenuator its a pot with mechanical steps so you could remove that mechanism ?.

I had a quad system and loved the classic looks of it
The 34 suits the very revealing 306 amp very well but on its own with a transparent power amp it sound a bit bland and veiled IMO.

Alan

[Idlewithnodrive]

The 34 pre does divide opinion, no doubt but I haven't found it particularly veiled or pipe and slippers but I'm also pretty sure that my high frequency hearing isn't as good as it should be.

[mikmas]

This makes am interesting read:

https://pinkfishmedia.net/forum/threads/quad-34-volume-sensitivity.140901/

Particularly the comment from 'Robert' further down the thread:

"On the volume pot, its an oddity in that it consists of laser etched resistive 'lands' instead of a continuous track and behaves exactly like a stepped attenuator.
The lands themselves carry different values instead of the hard wired resistors you'd normally find.
You'll find there is no intermediate setting between clicks even if you try to gently set the control between positions."

(Doncha just love Google :lol:)

[Idlewithnodrive]

Thanks for that Mike, that's very interesting. It looks like I won't be able to 'modify' the volume control after all :/

[Stryder5]

I think it was said earlier that you can vary the output gain by changing two resistors, it may be that doing this you could come to a setting that suits your listening levels.

If the above is correct could you use a pair of miniature pots instead?

I too am using Google as my source of knowledge:), as I am dumb as far as electronics are concerned!

Gary

Is it worth the hassle, only you can decide.

[Idlewithnodrive]

It's not the absolute volume level that is the problem Gary.

It is that the volume differential between steps is too great, so I often find a track is just a bit too loud or just a bit too quiet.

[Firebottle]

All is not lost, there is a possible solution which would be fully reversible back to the original pot.

However the 'law' of the volume increase would probably be not exactly matched to the standard logarithmic response of a standard B pot.
By fitting a standard replacement pot the active volume stage would still function, then judicious choice of padding resistor on the pot would approximate a logarithmic response.

The original can always be retro fitted without problem.

[Stryder5]

It's not the absolute volume level that is the problem Gary.

It is that the volume differential between steps is too great, so I often find a track is just a bit too loud or just a bit too quiet.

I wasn't clear, by changing the resistor values you could arrive at one of the 'lands' that was suitable for you, not the absolute level.

Gary

[walpurgis]

If you're using only half the volume control's travel, reducing the overall gain would allow you to use more of its travel and the step sizes would be effectively smaller

The same thought crossed my mind.

Rather like changing down a gear in a car! :D

[Idlewithnodrive]

If you're using only half the volume control's travel, reducing the overall gain would allow you to use more of its travel and the step sizes would be effectively smaller. It's worth considering. What's the maximum setting you ever use?

Ah, now I see. That makes perfect sense.

The max volume I use is about 60 - 65%

[Idlewithnodrive]

Yep, 21 steps and, usually, 13 max.