Author Topic: Choke values to suit Mingda amp  (Read 3882 times)

Offline flemo

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Choke values to suit Mingda amp
« on: September 01, 2011, 09:14:49 PM »
In the quest to squeeze every bit of performance out my Mingda MC34-AB amp I want to upgrade the chokes to vintage oil filled chokes.  8)

I have been able to identify through a Chinenglish schematic the chokes are rated at 5H & 800MA.  I can accept the 5H as accurate, but the 800MA seems way off given my very limited knowledge on electronics.   :o  I'd like to think maybe it's a typo or poor translation, and assume perhaps they would be 80MA?

My querie for you tech savvy guys is can I use higher rated chokes without causing any damage and/or a detriment to the sound reproduction? 

Would using chokes rated valued at 10H & 200MA be worthwhile or pointless if the values aren't specifically matched?

I look forward to your opinions.

Cheers, flemo. 

Offline ozcal

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Re: Choke values to suit Mingda amp
« Reply #1 on: September 01, 2011, 09:23:33 PM »
Pete , been reading up on chokes and depending on how much of the circuit the choke is regulating 800ma may not be a misprint but I don't really know.
Here's a link to a 5h 500ma choke : http://www.analogmetric.com/goods.php?id=1274
Ps , the DCR or dc resistance of the choke is apparently important too.
Listening with my ears :)

Offline flemo

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Re: Choke values to suit Mingda amp
« Reply #2 on: September 01, 2011, 09:34:44 PM »
800ma may not be a misprint but I don't really know.

Yepp that's the real bugger, is it accurate or not.  You don't see many chokes rated at 800MA and that's what sort of made me wonder if it was a typo.  I discussed it with JB and he considered 800MA to be very high, but not out of the realm. He suggested the last resort may be to measure it under load, like I know how to do that!! :o 

Offline kajak12

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Re: Choke values to suit Mingda amp
« Reply #3 on: September 01, 2011, 09:45:27 PM »
800ma may not be a misprint but I don't really know.

Yepp that's the real bugger, is it accurate or not.  You don't see many chokes rated at 800MA and that's what sort of made me wonder if it was a typo.  I discussed it with JB and he considered 800MA to be very high, but not out of the realm. He suggested the last resort may be to measure it under load, like I know how to do that!! :o 
Flemo i have some chokes here from my amp which i dont use we can try them on your minda if they catch on fire just blow  :o :o :o
still discovering the link between electronics and audio reproduction.so much to learn and so little time

Offline flemo

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Re: Choke values to suit Mingda amp
« Reply #4 on: September 01, 2011, 09:52:09 PM »
800ma may not be a misprint but I don't really know.

Yepp that's the real bugger, is it accurate or not.  You don't see many chokes rated at 800MA and that's what sort of made me wonder if it was a typo.  I discussed it with JB and he considered 800MA to be very high, but not out of the realm. He suggested the last resort may be to measure it under load, like I know how to do that!! :o 
Flemo i have some chokes here from my amp which i dont use we can try them on your minda if they catch on fire just blow  :o :o :o

Okay sounds good Mario apart from the fire bit, was looking for a more scientific approach but why start now!!  :D  What values are they? 

Offline kajak12

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Re: Choke values to suit Mingda amp
« Reply #5 on: September 01, 2011, 10:12:19 PM »
800ma may not be a misprint but I don't really know.

Yepp that's the real bugger, is it accurate or not.  You don't see many chokes rated at 800MA and that's what sort of made me wonder if it was a typo.  I discussed it with JB and he considered 800MA to be very high, but not out of the realm. He suggested the last resort may be to measure it under load, like I know how to do that!! :o 
Flemo i have some chokes here from my amp which i dont use we can try them on your minda if they catch on fire just blow  :o :o :o

Okay sounds good Mario apart from the fire bit, was looking for a more scientific approach but why start now!!  :D  What values are they? 
About 10h i have no idea on MA but they worked in my amp,which supply a lot more tubes then yours  ;)
still discovering the link between electronics and audio reproduction.so much to learn and so little time

Offline Jehuty

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Re: Choke values to suit Mingda amp
« Reply #6 on: September 02, 2011, 10:36:34 PM »
800ma may not be a misprint but I don't really know.

Yepp that's the real bugger, is it accurate or not.  You don't see many chokes rated at 800MA and that's what sort of made me wonder if it was a typo.  I discussed it with JB and he considered 800MA to be very high, but not out of the realm. He suggested the last resort may be to measure it under load, like I know how to do that!! :o 
Flemo i have some chokes here from my amp which i dont use we can try them on your minda if they catch on fire just blow  :o :o :o

Oh no.... Don't blow the chokes Mario, I love vintage chokes, been collecting them since I got my kdac and now I need more chokes than ever as I am going to build amps like Steve's. What chokes do you have Mario? UTC? Chicago? If they don't suit flemo's amp I may want to get them.
Not all that matters can be measured, not all that can be measured matters.

Offline kajak12

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Re: Choke values to suit Mingda amp
« Reply #7 on: September 02, 2011, 11:14:59 PM »
800ma may not be a misprint but I don't really know.

Yepp that's the real bugger, is it accurate or not.  You don't see many chokes rated at 800MA and that's what sort of made me wonder if it was a typo.  I discussed it with JB and he considered 800MA to be very high, but not out of the realm. He suggested the last resort may be to measure it under load, like I know how to do that!! :o 
Flemo i have some chokes here from my amp which i dont use we can try them on your minda if they catch on fire just blow  :o :o :o

Oh no.... Don't blow the chokes Mario, I love vintage chokes, been collecting them since I got my kdac and now I need more chokes than ever as I am going to build amps like Steve's. What chokes do you have Mario? UTC? Chicago? If they don't suit flemo's amp I may want to get them.
no idea what chokes they are jehunty nothing is written on them
still discovering the link between electronics and audio reproduction.so much to learn and so little time

tuyen

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Re: Choke values to suit Mingda amp
« Reply #8 on: September 03, 2011, 09:49:23 AM »
Hi Pete,

These aren't potted or oil filled but they are vintage and made for a valve amp!   I have had them for a while. Was going to use them in my AudioNote 300B SET rebuild.. but probably won't anymore...   happy for you to try if you like :)     Also, unsure what values they are!




Offline flemo

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Re: Choke values to suit Mingda amp
« Reply #9 on: September 03, 2011, 12:18:15 PM »
Hi Tuyen,

Thanks for the offer mate and more than happy to give them a try.   8)

How old do you reckon they are? 


Offline kajak12

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Re: Choke values to suit Mingda amp
« Reply #10 on: September 03, 2011, 01:52:20 PM »
Hi Tuyen,

Thanks for the offer mate and more than happy to give them a try.   8)

How old do you reckon they are? 


JUST BY LOOKING AT THEM OLDER THEN YOU FLEMO 8)
still discovering the link between electronics and audio reproduction.so much to learn and so little time

Offline flemo

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Re: Choke values to suit Mingda amp
« Reply #11 on: September 03, 2011, 04:47:52 PM »
Hi Tuyen,

Thanks for the offer mate and more than happy to give them a try.   8)

How old do you reckon they are? 


JUST BY LOOKING AT THEM OLDER THEN YOU FLEMO 8)

Sh*t they must be pretty freakin' old then!!  ???