Quad 33 help please

[Bbdave]

No, just repair it. Superglue the two bakelite parts and solder bridges would in most cases suffice. A photo will tell what can be done.

I could have a go at repairing it i assumed that as it had 4 sides the damaged one would be bypassed I guess not, would this be the broken channel my father mentioned?

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Dave

[Barry]

Each side of the card corresponds to pick up cartridges having different sensitivities and requiring different equalisation. The damage affects three sides of the card, so the only side not affected is the one shown at the top.

Looking at an enlargement of the second photo it would appear that the circuitry corresponding to those sides to the left and to the right are undamaged, but I would have to see a much larger photo, and to see what cartridges they cater for (that is, to see the corner markings: C; or M1, and M2. Only the side which is unpopulated by components (and marked as S1) is damaged, but this side will now be used.

However this damaged side will make it difficult to insert the card, so a replacement is recommended; repair using superglue is unlikely to be a long-term fix, especially if the card is to unplugged and replugged several times.

[chartz]

Inspect the motherboard too. The broken board isn’t beyond repair anyway!

[Bbdave]

Inspect the motherboard too. The broken board isn’t beyond repair anyway!

Which one is the motherboard?.

Dave

[chartz]

The one that sits at the base of the preamp, that occupies the whole surface!

[Barry]

When fitted the square disc sensitivity card protrudes from the back of the preamp so it can be easily removed and reinserted with a different side if required. Looking at the damage it would appear that the preamp was dropped and that part of the disc selection card which protrudes has broken off.

The undamaged side (at the top of the photo) is for M1, corresponding to a fixed-magnet cartridge having a low output of 0.5 - 2.0 mV/cm/sec, which is typical of a good quality magnetic cartridge such as was used by the previous owner and one benefiting use in an SME arm. So since the side of the disc selection board is undamaged for such a cartridge it could easily be refitted when the cover of the Quad 33 is removed.

Whilst you have the cover of the preamp off to inspect the mother board, it might be a good idea to remove in turn the three vertical circuit boards that are plugged into the mother board, clean the respective multi-way connector with some aerosol switch cleaner and reinsert the board.

[Bbdave]

Thanks chaps I have a new pcb on its way to try.

Onto the next bit to sort is the tonearm I have ordered some bits to convert it to RCA plugs, but I need a new cartridge any reccomendations? I dont want anything to pricey as I dont want to damage it whilst I set it up.
Also which set up protractor do I need i see there are different types im fitting it to a TD160 B Mk2. The sme serial No.94692

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Dave

[chartz]

The 3200XE was a superb cartridge. I still use one on my B790.
Stick to AT. A VM95EN or ML if budget allows.

[Barry]

I would agree; try any of the Audio Technika cartridges as suggested by Jacques, they should not be too expensive.

Regarding the SME arm, since it looks to be an early model it might be designed to follow the Stephenson prescription to minimise the tracking error. Later versions were changed so as to require the Baerwald prescription to minimise the tracking error. You need to know the serial number (as marked on the underside of the bedplate): if less than 439606 the Sephenson prescription applies, if it is 439606 or greater use the Baerwald prescription.

[Bbdave]

I would agree; try any of the Audio Technika cartridges as suggested by Jacques, they should not be too expensive.

Regarding the SME arm, since it looks to be an early model it might be designed to follow the Stephenson prescription to minimise the tracking error. Later versions were changed so as to require the Baerwald prescription to minimise the tracking error. You need to know the serial number (as marked on the underside of the bedplate): if less than 439606 the Sephenson prescription applies, if it is 439606 or greater use the Baerwald prescription.

The serial is 94692 so I guess definitely the lower so the Stephenson prescription (no idea what that means so something else to google).

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Dave