Murata reg for Caiman

[robyonekenoby]

Hello, I'm going to replace the 7805 with the murata 7805sr

My local dealer has two model, 0.5 ampere and 2 ampere

May I go for the smaller one? No idea about the total 5V section current requirement

thanks

[StanleyB]

Can you let us know the part number of the ones your local supplier has? There are a couple of different versions. The horizontal PCB versions won't fit!

[robyonekenoby]

Hi Stan,

Actually they have two different versions for 0.5 A

7805SRH-C and 7805SR-C

[Reid Malenfant]

Having had a quick think about the present circuit i'd say that the 0.5A regulator should be sufficient You might well need to remove the resistor feeding the standard regulator input as i think i remember someone mentioning they need a higher input voltage to give the 5V output

I'd check the specs of both regulators though. Obviously you are attempting to improve things & you might well find the higher current version would do a better job at the end of the day

[robyonekenoby]

Hi Mark,

so you suggest to go for the 2A version, but is quite larger, not sure it fit in the box

[Reid Malenfant]

No, i said look at the specifications & see which has the lowest noise, ripple on the output etc

The 0.5A reg is man enough for the job, it doesn't mean it's the better regulator though, for that you need to look a little deeper

[HighFidelityGuy]

You want the 7805SR-C. The 7805SRH-C is the horizontal version which as Stan said won't fit. Also, as Mark said you can replace the resistor behind the 5V reg with a wire link as the Murata has a wider input voltage tollerance and so doen't require the resistor.

[robyonekenoby]

Thanks Dave, I put it on order right now

Plus a Nichicon OS-CON 220uF to replace the cap after the regulator and a 100uF ceramic multilayer in place of the tiny cheap 100uF electrolitc in the dac area

[Gazjam]

You want the 7805SR-C. The 7805SRH-C is the horizontal version which as Stan said won't fit. Also, as Mark said you can replace the resistor behind the 5V reg with a wire link as the Murata has a wider input voltage tollerance and so doen't require the resistor.

Hey Dave,
I've got both the Mutara's fitted to my Passive Mod Caiman, and I've not done this "wire link" yet.
Sounds like i should!

How would I go about it...?
Is there a good pic on any of the threads showing where to remove the resistor?
Is it just a case of snipping the legs and soldering in a wire link?
Any reasonable hookup wire do the job?

Is it feasable for a soldering noob like myself to do?

Also, does removing the resistor make the Mutara work "better", i.e. an improvement in sound?


Thanks (and sorry for the dumbo questions!)
gary.

[HighFidelityGuy]

Hey Dave,
I've got both the Mutara's fitted to my Passive Mod Caiman, and I've not done this "wire link" yet.
Sounds like i should!

How would I go about it...?
Is there a good pic on any of the threads showing where to remove the resistor?
Is it just a case of snipping the legs and soldering in a wire link?
Any reasonable hookup wire do the job?

Is it feasable for a soldering noob like myself to do?

Also, does removing the resistor make the Mutara work "better", i.e. an improvement in sound?


Thanks (and sorry for the dumbo questions!)
gary.

Hi Gary,

Here's a photo that shows the resistor:



It's the beige one in the top left hand corner directly between the space where the 5V reg goes and the RCA sockets.

As for whether replacing it with a wire link will make any difference to sound quality I wouldn't have thought so but Stan is the best person to ask. I think it's just that the resistor was required for the old reg but isn't really for the Murata. I doubt that leaving it in will cause enough voltage drop to lower the Caiman's 15V input to below the 7805SR-C's dropout voltage of 7.5V. So personally I wouldn't take the whole thing to bit's just to do that one thing but it's up to you.