Meridian 551 schematic

[F575M]

Does anyone out there have the circuit diagrams for the 551 Integrated Amplifier? I am trying to find out if there is a 110V tap on the primary or if the switch mode power supply is a universal one. Lots of switch mode supplies take anything from 90 to 250 volts AC with no changes.

Cheers,

[Firebottle]

I've looked at the user manual and it states to make sure the unit is set to the correct voltage, so I guess that rules out a universal switch mode supply.

Annoyingly there is no mention of how to check or change the voltage in the unit.

Perhaps lift the lid and see if there is 1) a conventional transformer inside, 2) any switch of tags for voltage adjustment.

Post a pic if you need assistance.

[Pieoftheday]

I just googled meridian 551 schematic and they were lots of photos, diagrams pop up, they meant bugger all to me mind

[Firebottle]

Just had another look at one of the photos.
There is a large toroidal transformer with possibly 4 wires on the primary mains input.
These would have to be wired correctly for 120V or 240V operation, 2x 120V primaries in parallel or series.

[Mr.Ian]

Just had another look at one of the photos.
There is a large toroidal transformer with possibly 4 wires on the primary mains input.
These would have to be wired correctly for 120V or 240V operation, 2x 120V primaries in parallel or series.

Looking at some of the threads on Hitchhikers where people in the US were adapting voltages they were swapping out transformers. There is a note in the sales blurb that might also support the need for a transfer swap out

"The power amplifier uses a unique feedback topology and precision local error correction system. It is designed and constructed in dual mono format, including a massive twin wound toroidal transformer."

[F575M]

I do not have one, I am trying to get rid of my separates and buy an integrated. A chap in Stirling is selling a mint 551 with an MC card. I can buy a step-up transformer, they are practically inexpensive, but I will be adding another piece of equipment to my system and that is what I am trying to avoid.

Meridian and British components are easy to find in Canada, which uses 110V, but Canadians do not like to ship to the States. Most do not accept PayPal, they accept Interac/EMT a form of payment not available in the States.

[Macca]

Try e-mailing these people (if you didn't already) https://www.the-repair-shop.com/meridian

[F575M]

I already e-mailed them. Thank you.

Would I be able to use my AT33PTG [0.3 mV (at 1 kHz, 5 cm/sec]. Please look at the LP MC gain:

Gain LP MC

0dB 210μV
03dB 150μV
06dB 110μV
09dB 75μV
12dB 54μV
15dB 38μV