Hi All
Thought i'd chance a question....
I have a Musical Fidelity X-A1 that has given great service for the last 5 years, but after listening to my friends Exposure amp, I want to inject a bit more life into the mix.
Has anybody set about one of these creatures? What mods make sense , and are there any recommendations other than getting another amp..... What about capacitor upgrades? What about anything upgrades!!!
I am easy with a soldering iron, so no mod too big
Thought i'd chance a question....
I have a Musical Fidelity X-A1 that has given great service for the last 5 years, but after listening to my friends Exposure amp, I want to inject a bit more life into the mix.
Has anybody set about one of these creatures? What mods make sense , and are there any recommendations other than getting another amp..... What about capacitor upgrades? What about anything upgrades!!!
I am easy with a soldering iron, so no mod too big
OK! not a resounding success......
I have had a look inside, the unit, and it has cheapo caps, and ceramics. What are the best reasonable capacitors for the price, and also where can I get them in the UK, or easily through the web please?
Does anyone have a component list to hand also, otherwise, I will compose one....
I have had a look inside, the unit, and it has cheapo caps, and ceramics. What are the best reasonable capacitors for the price, and also where can I get them in the UK, or easily through the web please?
Does anyone have a component list to hand also, otherwise, I will compose one....
Update, and advice needed.
1. Replaced elctrolytics with Blackgates, that brought about an immediate clarity to the sound. Solid bass, and better resolution.
2. Replaced all 47pf ceramics with RS 113-241 Polystyrene axial capacitor, 47pF 160Vdc that introduced serious distortion. Should I have used something else? If so please tell me what. Ceramics put back in.
3. Placed a few WIMA FKP2 radial polyprop cap,220,330,470pF 100Vdc in place of ceramics. Sound is much clearer, but there seems to be a slight hardening in the upper frequencies. I have not replaced them all, as I am concerned on an imbalance. What would you advise to replace with?
4. There is an SEP BR104 Bridge rectifier. What would you replace this with?
I am having much fun with this, so am looking to go as far as I can.
Any help much appreciated.
Adam
1. Replaced elctrolytics with Blackgates, that brought about an immediate clarity to the sound. Solid bass, and better resolution.
2. Replaced all 47pf ceramics with RS 113-241 Polystyrene axial capacitor, 47pF 160Vdc that introduced serious distortion. Should I have used something else? If so please tell me what. Ceramics put back in.
3. Placed a few WIMA FKP2 radial polyprop cap,220,330,470pF 100Vdc in place of ceramics. Sound is much clearer, but there seems to be a slight hardening in the upper frequencies. I have not replaced them all, as I am concerned on an imbalance. What would you advise to replace with?
4. There is an SEP BR104 Bridge rectifier. What would you replace this with?
I am having much fun with this, so am looking to go as far as I can.
Any help much appreciated.
Adam
Hi,
ceramics have very variable characteristics.
Ceramics in general cannot be avoided for VHF circuits.
Some ceramics perform VERY well in audio circuits.
NP0 (=C0G) ceramics have excellent stability and accuracy. Their only downfall (that I am aware of) is their variation with applied voltage. This makes them supreme above all else for bypass duty where they see a constant voltage while operating.
They can also be used in the audio signal transfer side of the circuit if selected appropriately.
I suspect your 47pF were NP0 and that they had been correctly chosen for their duty. MF do not usually make mistakes like that.
The PP substitute may benefit from a parallel decoupling using a smaller cap under the PCB. Either a small PP or a NP0 ceramic. Two different di-electrics may return balance.
Have a look at your feedback loop and at your input filter. They can often be improved.
ceramics have very variable characteristics.
Ceramics in general cannot be avoided for VHF circuits.
Some ceramics perform VERY well in audio circuits.
NP0 (=C0G) ceramics have excellent stability and accuracy. Their only downfall (that I am aware of) is their variation with applied voltage. This makes them supreme above all else for bypass duty where they see a constant voltage while operating.
They can also be used in the audio signal transfer side of the circuit if selected appropriately.
I suspect your 47pF were NP0 and that they had been correctly chosen for their duty. MF do not usually make mistakes like that.
The PP substitute may benefit from a parallel decoupling using a smaller cap under the PCB. Either a small PP or a NP0 ceramic. Two different di-electrics may return balance.
Have a look at your feedback loop and at your input filter. They can often be improved.
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