Denon DP-47f transformer

[NachoTemino]

Hi,

I managed to get a very good looking DP-47f for a reasonable price (200€). It is one of those japanese 100v model and everything works fine.

I have a completely useless 230v (I'm in Europe) DP-23f (fried tonearm motor) and I wonder if I could replace the 100v transformer of the DP-47f with the 230v of the 23f and get rid of the external stepdown transformer. I have measured the European model and it gives 15v switched off and 12v switched on, same as the japanese outputs. Wiring to the PCB is just a one by one replacement.

Should I dare?

 

[Aerobat]

If all the transformers are doing is stepping down to 12VAC I don't see why not.

 

[NachoTemino]

That is my thought too. As per turntables specs, DP23 is 7W and DP47 is 8W. I believe that difference is insignificant.

 

[Sleiven]

Be careful, the 51F I have is very different in the 100V and 230V version. It is doing more than stepping down voltage .
The motor is directly connected to the wall power in the 100V version. Do not do this unless you understand the two different service manual schematics 100%.
Have not checked the 21F , I think it may have a different motor system , so you may be ok , but see the schematic, here is 47 , not the same as 51F I see, so the 51F case us maybe not relevant here
47F




51F

 

[NachoTemino]

Thank you Sleiven. In the case of the 47f I see no difference between in the schematics, I downloaded the 51f SM and It is true that the 51f looks quite different.
This is 23f:


And this is 47f


I am no expert, but I have done some minor electronic surgery in my turntables. Both schematics look very similar to my eye. The only thing that catch my eye is the in the 47f there are two 1000uf/25V caps in the circuit and in the23f one is 1000/25 and the other one is 2200/25

 

[Sleiven]

You schematic Show that my concern regarding a 51F type problem is not valid.

I did a different thing with my Fisher 6330, I used an external DC supply and added a Regulator from AliExpress , and got more stable DC then the transformer+rectifier made. Did nothing audible for the sound, but theoretically better

DD turntable with AC internal power and external DC supply. Connected it downstream the rectifier and across the main power supply capacitor . At your own risk!

 

[NachoTemino]

That's clever!

 

[Aerobat]

I outboarded the power supply on a HK T-55C. Getting it away from the signal circuit and arm is a good thing.