Is there a better resistor than these ceramic coil ones?
Doing a recap on my Emotiva Airmotiv6.
2cm length, 2cm height, 0.5cm width.
Two Leads.
Would replace it with Mundorf M-Resist, but it's too big and costly.
Help would be appreciated.
Doing a recap on my Emotiva Airmotiv6.
2cm length, 2cm height, 0.5cm width.
Two Leads.
An externally hosted image should be here but it was not working when we last tested it.
Would replace it with Mundorf M-Resist, but it's too big and costly.
Help would be appreciated.
Thanks so much for commenting Damon.
I've did some looking around and it seems to be a cement ceramic wirewound resistor:
Aliexpress.com : Buy 0.22 5w cement resistor ceramic resistor on China Electronics Wholesale.
Is it ok to go over the wattage rating? (eg. 10W, 15W, 20W)
I'll be sure to look for some emitter resistors with the lowest temperature coefficient.
Do these generally get hot?
I've heard cases where some output stage resistors would melt or run into heating issues which doesn't do justice for sound quality.
I've did some looking around and it seems to be a cement ceramic wirewound resistor:
Aliexpress.com : Buy 0.22 5w cement resistor ceramic resistor on China Electronics Wholesale.
Is it ok to go over the wattage rating? (eg. 10W, 15W, 20W)
I'll be sure to look for some emitter resistors with the lowest temperature coefficient.
Do these generally get hot?
I've heard cases where some output stage resistors would melt or run into heating issues which doesn't do justice for sound quality.
Higher wattage won't change anything except the size of the part; it may not be possible to fit neatly.
If actually dissipating five watts, yes, they'll get rather warm. Normally, they should NOT get that hot. A discolored or smoking hot resistor is a sign of a problem elsewhere--resistors are passive devices and don't fail like this on their own. I would leave them as is; a replacement resistor ought to be spaced away from the board on it's own extended leads for better dissipation. No more than half an inch or so should do it.
If actually dissipating five watts, yes, they'll get rather warm. Normally, they should NOT get that hot. A discolored or smoking hot resistor is a sign of a problem elsewhere--resistors are passive devices and don't fail like this on their own. I would leave them as is; a replacement resistor ought to be spaced away from the board on it's own extended leads for better dissipation. No more than half an inch or so should do it.
Oh, so the only time WORTH replacing a resistor like this is if it's discolored or have an overly high temperature coefficient. i see i see.
Let's say i went with Mundorf M-Resist Supreme which is rated at 20W.
Being 50mm long, it's not going to have that "clean fit".
So i was thinking, is it okay to mount on top of each other (piggyback) or would it not be recommended since the leads are too long and can be distorted by EMI signals.
Sorry for all the questions.
I'm doing a recap on my studio speakers (Emotiva Airmotiv6) and it's kind of a one-time thing. Just trying to get the best performance out of them since i'm not going to be buying/upgrading speakers for another 5-7 years.
So far i have replaced all Micon (Chinese brand) capacitors with Elna Silmic II, film capacitors (yellow/blue colored Chinese brand) with WIMA FKP2/MKP2 (some MKS2 as capacitance is too high).
Hope i'm doing it right. Your comments are highly taken into account.
I kept the same capacitance/voltage. The main improvement i'm going for with the film cap changes is swapping out those cheap Chinese polyesters with a higher polypropylene dielectric cap.
Let's say i went with Mundorf M-Resist Supreme which is rated at 20W.
Being 50mm long, it's not going to have that "clean fit".
So i was thinking, is it okay to mount on top of each other (piggyback) or would it not be recommended since the leads are too long and can be distorted by EMI signals.
An externally hosted image should be here but it was not working when we last tested it.
Sorry for all the questions.
I'm doing a recap on my studio speakers (Emotiva Airmotiv6) and it's kind of a one-time thing. Just trying to get the best performance out of them since i'm not going to be buying/upgrading speakers for another 5-7 years.
So far i have replaced all Micon (Chinese brand) capacitors with Elna Silmic II, film capacitors (yellow/blue colored Chinese brand) with WIMA FKP2/MKP2 (some MKS2 as capacitance is too high).
Hope i'm doing it right. Your comments are highly taken into account.
I kept the same capacitance/voltage. The main improvement i'm going for with the film cap changes is swapping out those cheap Chinese polyesters with a higher polypropylene dielectric cap.
I really wouldn't change those resistors.
With SMD components on the board, the length of the resistor leads would be massive compared to the rest.
If your concerned about the heat, make up some new U shaped clamps for the output transistors, incorporate heatsinking and physical stability for the resistors.
With SMD components on the board, the length of the resistor leads would be massive compared to the rest.
If your concerned about the heat, make up some new U shaped clamps for the output transistors, incorporate heatsinking and physical stability for the resistors.
I was mainly concern with the sound quality if changing them would present any sonic gains, but since it doesn't, it's most likely going to be left alone.
Underneath the PCB near the resistors, there are multiple MOSFETS or Output Transistors that are equipped to the large anodized heatsink (behind the speaker). I don't think heat would be an issue.
Thanks for the commenting whizgeek.
Guess there's no upgrades i can do other than changing out capacitors.
Perhaps changing out copper wires with pure silver is another upgrade.
Underneath the PCB near the resistors, there are multiple MOSFETS or Output Transistors that are equipped to the large anodized heatsink (behind the speaker). I don't think heat would be an issue.
Thanks for the commenting whizgeek.
Guess there's no upgrades i can do other than changing out capacitors.
Perhaps changing out copper wires with pure silver is another upgrade.
On Ebay, use a search string such as "0.22 ohm 1% wirewound" 0.25 ohm turns up a few more choices. Also search with Vishay, Dale, or Mills, and see what turns up. It may take a while, and you might find it helpful to exclude terms: -carbon -smd etc.
The Usual Suspects (your pricey audiophile parts stockist) will stock Mills, such as percyaudio.com
But it never hurts to cruise Ebay and see if someone's got good parts at better prices. If I weren't chronically broke I'd be picking up a bunch of Russian polystyrene 1% or better caps for calibration standards, for example.
The Usual Suspects (your pricey audiophile parts stockist) will stock Mills, such as percyaudio.com
But it never hurts to cruise Ebay and see if someone's got good parts at better prices. If I weren't chronically broke I'd be picking up a bunch of Russian polystyrene 1% or better caps for calibration standards, for example.
A higher wattage wont get as hot for the same temperature input.
If I need a 5 watt resistor I usually use a 10 watt resistor to keep the temperature down a bit. While the same amount of heat is dissipated it is done over a wider area and so runs cooler.
While these resistor will stand a lot of heat sometimes they can get hot enough to melt their mounting solder if run near their limit !
I found the following:
1. 5W, 1% Tolerance, 90 PPM/C, and -65 C to +250 C
RS005R2200FE12 Vishay/Dale | Mouser
2. 5W, 1% Tolerance, 90 PPM/C, and -65 C to +275 C
LVR05R2200FE12 Vishay/Dale | Mouser
Stock 5% versus 1%
Stock 400PPM/C versus 90 PPM/C
Stock -55 C to +155 C versus -65 C to +250 C
Do you think it's an upgrade? Or maybe i can find some even better.
I need 8 overall (4 for each speaker).
1. 5W, 1% Tolerance, 90 PPM/C, and -65 C to +250 C
RS005R2200FE12 Vishay/Dale | Mouser
2. 5W, 1% Tolerance, 90 PPM/C, and -65 C to +275 C
LVR05R2200FE12 Vishay/Dale | Mouser
Stock 5% versus 1%
Stock 400PPM/C versus 90 PPM/C
Stock -55 C to +155 C versus -65 C to +250 C
Do you think it's an upgrade? Or maybe i can find some even better.
I need 8 overall (4 for each speaker).
Last edited:
I would like to thank everyone for their help.
I've decided to go with the Vishay/Mills MRA-Series Resistor.
Either MRA-10R2200FE12 or MRA-05R2200FE12
• Wirewound, Non-magnetic and all welded constructions
greatly enhance frequency response.
Combined with non-inductive Ayrton-Perry
winding the inductive reactance and signal loss
are almost totally eliminated.
• Ideal for Audio Industry
• High temperature coating (> 350 °C)
A little confused whether or not the MRA-05 is enough since it shows power rating of 4W and 5W. 4W being too low, so i was looking at the MRA-10 which does 7W.
Emailed Vishay, but still haven't received a response.
If i can get one sooner from people who know, that would be great.
Here is the datasheet:
http://www.vishay.com/docs/31801/mra.pdf
I've decided to go with the Vishay/Mills MRA-Series Resistor.
Either MRA-10R2200FE12 or MRA-05R2200FE12
• Wirewound, Non-magnetic and all welded constructions
greatly enhance frequency response.
Combined with non-inductive Ayrton-Perry
winding the inductive reactance and signal loss
are almost totally eliminated.
• Ideal for Audio Industry
• High temperature coating (> 350 °C)
A little confused whether or not the MRA-05 is enough since it shows power rating of 4W and 5W. 4W being too low, so i was looking at the MRA-10 which does 7W.
Emailed Vishay, but still haven't received a response.
If i can get one sooner from people who know, that would be great.
Here is the datasheet:
http://www.vishay.com/docs/31801/mra.pdf
The power rating is more than adequate in this application--the resistor won't get that hot in normal use. Just space the resistor off the board by about half an inch for heat dissipation.
I doubt you'll hear a difference given that are more critical parts in the circuit, but let us know what you think. Certainly not worth the price of Dueland or other boutique parts.
I doubt you'll hear a difference given that are more critical parts in the circuit, but let us know what you think. Certainly not worth the price of Dueland or other boutique parts.
Ah, so going for a low temperature coefficient is ideal, but when it hits the negatives, things get bad?
I'm currently looking to replace some four WIMA MKP-4's with some Axial Capacitors.
This tread is really helpful: Humble Homemade Hifi
Isn't it ideal to have capacitors as low tolerance as possible as they're in the audio signal? Yet i see so many 5% and 10% getting high scores in the review.
I could understand why bypass caps and electrolytes doesn't need close tolerance as they're only for soothing and filling, but what about one that's actually coupling the signal?
I'm currently looking to replace some four WIMA MKP-4's with some Axial Capacitors.
This tread is really helpful: Humble Homemade Hifi
Isn't it ideal to have capacitors as low tolerance as possible as they're in the audio signal? Yet i see so many 5% and 10% getting high scores in the review.
I could understand why bypass caps and electrolytes doesn't need close tolerance as they're only for soothing and filling, but what about one that's actually coupling the signal?
Thermal runaway, even with MOSFETs, could be possible with a negative coefficient in this application. It's just the wrong thing to do.
Only filter circuits with precisely defined slopes truly benefit from close tolerance capacitors; what counts in most cases is the quality of the dielectric and the construction. Low internal inductance (all components, including wire, have resistance, inductance and capacitance no matter what their primary function is). It's not a bad thing to match pairs, though.
Can't see any good reason to replace the MKP-4 caps. You're just spending extra money; the hi-fi boutiques just love that! It's your nickel.
Only filter circuits with precisely defined slopes truly benefit from close tolerance capacitors; what counts in most cases is the quality of the dielectric and the construction. Low internal inductance (all components, including wire, have resistance, inductance and capacitance no matter what their primary function is). It's not a bad thing to match pairs, though.
Can't see any good reason to replace the MKP-4 caps. You're just spending extra money; the hi-fi boutiques just love that! It's your nickel.
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.