Hi all,
I’m looking for some advice from you guys or gals please.
I have a MusicalFidelity M3si integrated amplifier. It works great and I’m very happy with it, driving a pair of Focal Aria 905 speakers.
However, having bought an RME ADI-2 DAC FS which serves as an excellent pre-amp with a powerful DSP, I thought I would try driving the power amp in the M3si directly. So I disconnected my AVR that was connected to the HT input and plugged the line-out from the DAC into it, then did some back to back tests. The outcome is that directly driving the power amp is markedly better - for example vocals are much more clearer - even a normally cynical family member spotted the difference without being told what to look for.
So - that’s the next mod for me to make. But the problem is I still want to make use of the HT input for my AVR. So I took the lid off the amp to see how it was wired, hoping it would be a simple relay switching arrangement that bypasses the pre-amp and connects directly to the power amp. If so, then I’m competent enough to replicate it and convert one of the other inputs to do the same. Unfortunately the input selection is via a microprocessor controlled analogue switch IC, so not possible without circuit diagrams and ability to change the code in the cpu to replicate how the HT input is routed. But it is also apparent that the HT input still goes through some aspects of the pre-amp, even if it is just the switch IC, which isn’t ideal for what I’m trying to achieve in bypassing all pre-amp effects.
Given this, the question I have is whether I can disconnect the leads that go from a socket in the pre-amp over to the power amp (a very obvious pair of 2 channel leads about 8 inches long) and build my own 2 in 1 out switch, using some quality signal latching relays that connect straight to it?
I’d be grateful for any input from people who might have some insight.
PS I could buy the M6s PRX that achieves exactly what I want, but it’s £2600!
I’m looking for some advice from you guys or gals please.
I have a MusicalFidelity M3si integrated amplifier. It works great and I’m very happy with it, driving a pair of Focal Aria 905 speakers.
However, having bought an RME ADI-2 DAC FS which serves as an excellent pre-amp with a powerful DSP, I thought I would try driving the power amp in the M3si directly. So I disconnected my AVR that was connected to the HT input and plugged the line-out from the DAC into it, then did some back to back tests. The outcome is that directly driving the power amp is markedly better - for example vocals are much more clearer - even a normally cynical family member spotted the difference without being told what to look for.
So - that’s the next mod for me to make. But the problem is I still want to make use of the HT input for my AVR. So I took the lid off the amp to see how it was wired, hoping it would be a simple relay switching arrangement that bypasses the pre-amp and connects directly to the power amp. If so, then I’m competent enough to replicate it and convert one of the other inputs to do the same. Unfortunately the input selection is via a microprocessor controlled analogue switch IC, so not possible without circuit diagrams and ability to change the code in the cpu to replicate how the HT input is routed. But it is also apparent that the HT input still goes through some aspects of the pre-amp, even if it is just the switch IC, which isn’t ideal for what I’m trying to achieve in bypassing all pre-amp effects.
Given this, the question I have is whether I can disconnect the leads that go from a socket in the pre-amp over to the power amp (a very obvious pair of 2 channel leads about 8 inches long) and build my own 2 in 1 out switch, using some quality signal latching relays that connect straight to it?
I’d be grateful for any input from people who might have some insight.
PS I could buy the M6s PRX that achieves exactly what I want, but it’s £2600!
Basically, but you may need to look at input RF filters and DC blocking. Match the input impedance the feedback resistor and stuff. SOP if you read Self and Cordell.
Good to hear you like the MF. Some around here have been giving the " not what they used to be" line.
Good to hear you like the MF. Some around here have been giving the " not what they used to be" line.
Hi,
Thanks for your reply! I’ll look at that. Though an output from the RME DAC or Marantz AVR designed for line input to downstream amps should be sorted in those regards shouldn’t they?
In terms of MF, I don’t know of the history as it’s the only one I’ve ever owned, but I know that when I bought it I listened to 4 or 5 contenders at the price point and the MF stood out by a mile. Ymmv of course.
Thanks for your reply! I’ll look at that. Though an output from the RME DAC or Marantz AVR designed for line input to downstream amps should be sorted in those regards shouldn’t they?
In terms of MF, I don’t know of the history as it’s the only one I’ve ever owned, but I know that when I bought it I listened to 4 or 5 contenders at the price point and the MF stood out by a mile. Ymmv of course.
No, the are designed assuming the amp input is correctly designed. Might I suggest reading up on amp design. Cordell and Self. They discuss inputs in detail. Unless you are really experienced, best to get the schematic before making any assumptions.
I followed your recommendation and have read through relevant parts (and beyond). What fantastic works these are! In particular Douglas Self’s book has lots of useful and interesting content on physical considerations as well as electronic, and also on safety and protection mechanisms. My conclusion is not to dabble with the internals - even if I don’t muck it up electronically then I might circumvent a safety mechanism with disastrous results - so I’ll just use a 2 in 1 out converter on the HT input.
Many thanks for your pointers.
Many thanks for your pointers.