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QUAD 44 PREAMP: UPGRADES

Robert said:
Hi Mr T,

You did ask previously in relation to some needledrops IIRC. Those were all via tape out into the ADC.

How do you think these samples compare (to each other)?
Do both samples sound fine?
Click to expand...

They sound pretty much the same via laptop/headphones.

I'd like to compare a rip taken from the preamp output (proper!) to my own CD copy on my system - then I'd be able to settle this long standing nightmare that was my brush with the Quad 33 & 34 way back in the dim and distant past ;-)
 
Mr Tibbs said:
They sound pretty much the same via laptop/headphones.

I'd like to compare a rip taken from the preamp output (proper!) to my own CD copy on my system - then I'd be able to settle this long standing nightmare that was my brush with the Quad 33 & 34 way back in the dim and distant past ;-)
Click to expand...

Play those two samples through your system - I'll be interested to learn what you discover, and so will you :)
 
eguth said:
Apart from all this, I understand that Robert is seized of the wrong preamp. He uses a Quad ’34, not a ’44 for his revelations so they do not apply to this ’44 upgrade thread.
Click to expand...

Same circuit topology, same gain and buffer blocks, same tone/tilt circuit, same CMOS switching, same specification, and in Quad's own words, a 34 is a 44 for people requiring less inputs.

That makes any thread discussing one pre very applicable to the other.
 
"...Same circuit topology, same gain and buffer blocks, same tone/tilt circuit, same CMOS switching, same specification, and in Quad's own words, a 34 is a 44 for people requiring less inputs...That makes any thread discussing one pre very applicable to the other..."

This avoids mention of the differences between early and later versions.

Serial # of my ’44 is given in post #1, para 7. It was made before 1981. My upgrades are about this particular ’44.

Robert has not stated the serial number of the ’34 he uses. What is its number?

The ’34 did not appear on the market until 1982 so even if Robert’s ‘34 is serial # 1 it was produced after mine- which was made before 1981.

The point in time of production is relevant and could be important.

We have already seen that Quad embarked on an improvement programme almost immediately that resulted in better specs- indeed according to some- in better sound.

It would be a mistake for anyone trying my upgrades to think that the results obtained by my upgrades would be the same for a much later ’44. From this I except upgrades following the AC kinds of improvements outlined in post #29. These, indeed, might improve ANY preamp- not only a Quad.
 
I have been listening to Egyptian music from my Middle East LP collection; not only classics such as OM KALSOUM but also contemporary offerings such as from HOSSAM RAMZY. The latter is played on acoustic instruments – native ones such as the aud- together with western ones.

Although the recordings I have are often less than the best (I remember hearing music in Egypt that sounded better from the point of view of fidelity) you still need an excellent preamp if what I would describe as the ‘electric atmosphere’ of the music is to be present in your listening room.
The bog standard Quad ’44 presentation does not do justice to it.
 
eguth said:
"...Same circuit topology, same gain and buffer blocks, same tone/tilt circuit, same CMOS switching, same specification, and in Quad's own words, a 34 is a 44 for people requiring less inputs...That makes any thread discussing one pre very applicable to the other..."

This avoids mention of the differences between early and later versions.

Serial # of my ’44 is given in post #1, para 7. It was made before 1981. My upgrades are about this particular ’44.

Robert has not stated the serial number of the ’34 he uses. What is its number?

The ’34 did not appear on the market until 1982 so even if Robert’s ‘34 is serial # 1 it was produced after mine- which was made before 1981.

The point in time of production is relevant and could be important.

We have already seen that Quad embarked on an improvement programme almost immediately that resulted in better specs- indeed according to some- in better sound.

It would be a mistake for anyone trying my upgrades to think that the results obtained by my upgrades would be the same for a much later ’44. From this I except upgrades following the AC kinds of improvements outlined in post #29. These, indeed, might improve ANY preamp- not only a Quad.
Click to expand...

Splitting hairs. There is far more commonality between all models of 34/44 than there are differences.
Listen to the downloads and report back - youwill be interested in the results, I guarantee it.
 
Henry

I’m coming down to your next Audiojumble- even if I have to crawl on my hands & knees to get there. I need a knurled brass binding post for my 1920s doorbell; to replace a missing one.
 
Hi Eric.
My next event is in November.
The next event to come up is the Bracknell gig 17th April2011.

thamesvalleyaudiofayre.co.uk

Regards
Henry
 
I used a 44 with II's and 57s for years.

I thought the sound was great, a bit mushy, lacking in some detail
and air, and put that down to 40 year old power amps, I tweated the valves, cables, supports, had the 57s rebuilt all to try and correct this.

I realised I had wasted my money, when I got a Croft Vitale and plugged it
in. EVERYTHING improved, only then did I realise that the 44 was holding everything back.

The 44 could be good,love the voltage outputs, tilt, better than a 22 or 33
, but compared to the Croft it is like putting a woolly blanket over your speakers!
 
FWIW a number of years back I had an old DIN Quad 34, which I replaced just about every part on over a period of a year. It was rather 'warm & woolly' sounding before all the changes, I have to say.

When a family member unfortunately departed this mortal coil, I was left his Quad 34/606 system. This 34 was a 1989-era model and lightly used. Even stock it sounded as good as my highly modded early-model 34...

I shorted out a few caps that weren't needed in this 'new' 34, replaced all others with modern Panasonic FCs, signal path with Nichicon ES types, PSU with Rubycon ZLs and was very pleased with how it sounded indeed. Didn't change the op-amps or the CMOS switches like I did with my DIN model 34. I haven't a clue what revisions occured between the early 34s and the later ones, but I could quite clearly hear the differences.....
 
Lots of interesting comments.
I really, really do wish some would download and listen to those tracks.
It might well settle a 25 year old argument - just think we could be witnessing an internet forum first and history in the making! :)
 
Go on then! I find this sort of thing fascinating, so ...I've downloaded them, and neither's my kind of music, but B, to me, in both cases, sounds a bit darker, yet somehow coarser/messier than A. There's also a noticeable lift in the bass on B. I can't work out whether the bass sounds a bit slower and ploddy, or just that there's more of what is slightly boxy, boomy bass. I'd be wondering even if there was some slight tone control effect in place.

No idea where that fits into the story, but since one is presumably the signal routed through Rob's Quad 34, I'd be interested to know what the other is and, obviously, which is which!
 

MEMOIRS OF A DIY HI FI NUT - Part XVIX
QUAD 44 PREAMP: UPGRADES

IV

FURTHER UPWARDS!​

The summary of my AC article mods is finished. I move on to the later improvements.

However, before starting, I would like to expose you to two quotations from my old AC article.

1) “For about £50 the mediocre sound quality on DISC (MM) … was transformed to audiophile standards. The transformation astounded me…”
2) Quad, however, go into spasms whenever my mods are mentioned…”


MOVING MAGNET (DISC) MODULE

C316,317,304,305,306,307: improved with 4.7uF tantalum bead 50V replacements. C316,317 bypassed with .001 paper +0.01 Wondercap.
C310,311: 4.7uF polyester bypassed with .001 paper +0.1 uF 50V Black Gate NX
C312,313 polystyrene close tolerance (LXFS 1%)
C314,315 Audiocap 5%
Op amp replaced with AD847JN.

TAPE OUTPUT BOARD

Switches hard wired. All resistors replaced with Holcos.
C5,6 replaced with p/p
C7,8 with MIT .68uF 1% [matched]
Gold phono sockets installed, insulated from chassis and separately grounded (hard wired with silver wire to gold ground pins at far end of module pcb).
IC removed and replaced with OPA 134PA (Burr Brown).

STAR GROUNDING

Like most manufacturers, Quad use common grounds. This saves space, time and money. The ’44 modules are each grounded in common from the same narrow and thin PCB track. This compromised inferior grounding to each module does not result in the highest fidelity the circuit is capable of. Removing the common ground is a sonic revelation.

I admit to a bias against PCBs: whenever I can I modify or get rid of them.

In the case of the ’44 Mother Board there is no way out of the common ground compromise other than to make a better PCB or vandalise the old one. My preferred option was vandalism. I believe the vandalised result is superior to a redesigned board still using PCB tracks for grounding. So…I got out my chain saw… and...

All pcb ground tracks on the Mother Board were cut. Separate silver/ptfe insulated wires were individually soldered together and soldered to the first ground point on the Mother Board pcb. Then they were cut to size and each soldered to each module’s incoming ground connexion pin- i.e. every module was individually star grounded.

Crikey! What an improvement to the sound!

BYPASSES

0.1 uF Black Gate 50V NX(non- polarised) were purchased in large numbers and sprinkled everywhere, bypassing many other caps after reading what Martin Colloms said about them.

Next: deliberate destruction of the power supply. + a surgical operation on the chassis under general anaesthetic.
__________________________________________________
 
Grenadier_45 said:
Go on then! I find this sort of thing fascinating, so ...I've downloaded them, and neither's my kind of music, but B, to me, in both cases, sounds a bit darker, yet somehow coarser/messier than A. There's also a noticeable lift in the bass on B. I can't work out whether the bass sounds a bit slower and ploddy, or just that there's more of what is slightly boxy, boomy bass. I'd be wondering even if there was some slight tone control effect in place.

No idea where that fits into the story, but since one is presumably the signal routed through Rob's Quad 34, I'd be interested to know what the other is and, obviously, which is which!
Click to expand...

PM sent with answers.
 
I've just listened to them through the system and would largely agree with the thoughts of Grenadier. I've also listened again to my original CD copy and find it to be better than A or B - but not by much it has to be said.

Not sure what conclusion to draw from my findings though.....

Spill the beans Robert!

Mr Tibbs
 
Ok here we go.

Firstly, the listener preference isn't the important thing so nobody should feel they've chosen the wrong track. Differences and magnitudes are what count here.

B - Straight CD rip made using EAC. Probably as 'reference' as we can get for this test.

A- Same CD but via the following:

- Meridian 200 Cd player
- Analogue output taken to CD input of Quad pre
- Output of Quad taken from power amp out and into ADC to create digital file.

So effectively we have a straight rip against a chain of three components including the full path of the Quad. All tone controls were set flat.

Mr T, Grenadier and Tony L (previously) have listened to these files and there are differences identified. Indeed there should be given the path as none of these devices are perfect. The differences are however described as small.
What's interesting are the magnitude of the difference and that was the reason for doing this in the first place. I think that comments such as 'strangle the music', 'seriously restricted bandwidth' and 'make singers sound like they are face down on the carpet' needed to be challenged and hopefully this test does just that.

For complex, active pre amps, these things are actually very decent even stock.
The one used for the test had a recap and uses OPA134/2134 devices but is otherwise standard. It uses the original 4066 cmos switching (now changed).
 
eguth,
others should know your position on treating valves before they vandalise their own 44:

'I have tried Genelex Gold Lion KT77s, not KT66s. The ones I tried were cryogenically treated- which makes them better than the standard version.'

Mr Walker would not be impressed.

It baffles me why you would waste so much time trying to improve something so 'hopeless'. Why not buy a box and build your own pre-amp.
Modifying a Quad 44 like this reduces it to less than scrap value.
 
Robert said:
Ok here we go.

Firstly, the listener preference isn't the important thing so nobody should feel they've chosen the wrong track. Differences and magnitudes are what count here.

B - Straight CD rip made using EAC. Probably as 'reference' as we can get for this test.

A- Same CD but via the following:

- Meridian 200 Cd player
- Analogue output taken to CD input of Quad pre
- Output of Quad taken from power amp out and into ADC to create digital file.

So effectively we have a straight rip against a chain of three components including the full path of the Quad. All tone controls were set flat.

Mr T, Grenadier and Tony L (previously) have listened to these files and there are differences identified. Indeed there should be given the path as none of these devices are perfect. The differences are however described as small.
What's interesting are the magnitude of the difference and that was the reason for doing this in the first place. I think that comments such as 'strangle the music', 'seriously restricted bandwidth' and 'make singers sound like they are face down on the carpet' needed to be challenged and hopefully this test does just that.

For complex, active pre amps, these things are actually very decent even stock.
The one used for the test had a recap and uses OPA134/2134 devices but is otherwise standard. It uses the original 4066 cmos switching (now changed).
Click to expand...
I'm not sure comments such as 'strangle the music', 'seriously restricted bandwidth' and 'make singers sound like they are face down on the carpet' really need to be challenged at all. These are ridiculous comments, I suspect the majority of readers would dismiss them, particularly the 3rd of those comments.

There are a multitude of solutions available for those people serious about listening to music in the home and we don't all like the same thing. I thought a Quad setup I heard was good, I'm sure others would consider it to be not good at all. It's not a big deal. I'm sure some people wouldn't like my TVC or valve setup but I like it and so does my wife, which is all that matters.

Well done for posting the files and giving people the chance to comment but I'm sure you realise people capable of holding an opinion such as the 3rd one above is unlikely to be changing their mind soon. I may be surprised of course...we shall see. Don't lose any sleep over it and just enjoy listening to your music.
 
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