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Discrete Dynamics Amplifier:

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hydrovac

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Today, i got info from Aniket on what resistors to change.
Had to disassemble the amp to replace them.

1583430307306.jpeg

Nicely marked on the image... four resistors on bias side:
1583430343003.jpeg

12 resistors on output devices: will carry on the job tomorrow.
1583430323662.jpeg


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MaSh

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Oh why did you have to change? Blew them or an upgrade?

MaSh
 

kbhuvi

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Oh why did you have to change? Blew them or an upgrade?

MaSh
The original boards were designed for 40-0-40 volts.
Hydrovac is using 43-0-43. Due to the extra 3 volt the bias has changed and is effected by change in the resistors.

Me thinks. @hydrovac will confirm.
 

hydrovac

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Oh why did you have to change? Blew them or an upgrade?

MaSh
With the existing resistors, unable to bias... these are redesigned values.


The original boards were designed for 40-0-40 volts.
Hydrovac is using 43-0-43. Due to the extra 3 volt the bias has changed and is effected by change in the resistors.

Me thinks. @hydrovac will confirm.
True... but the boards were not designed for any particular voltage, the existing resistors were selected based on 40-0-40
input supply.

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hydrovac

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Changing of resistors done last evening... it was a challenging job accessing and removing them, with all the components around. But, soldering the new resistors from component side was next to impossible... moreover, i was having only 1/2 watt resistors, the pitch won't match.
I managed to pull it off like this, of course with Aniket's consent... it was too late to reassemble the amp.

1583552342285.jpeg

1583552495730.jpeg

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sadik

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Changing of resistors done last evening... it was a challenging job accessing and removing them, with all the components around. But, soldering the new resistors from component side was next to impossible... moreover, i was having only 1/2 watt resistors, the pitch won't match.
I managed to pull it off like this, of course with Aniket's consent... it was too late to reassemble the amp.

View attachment 44346

View attachment 44350

...
Repairing / changing components on a double layer PCB is a pain in @$$. U need proper tools and a helping hand too to pull out the parts/components. Apart from a good soldering Iron, Desoldering Pump is a must.
 

Kannan

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Changing of resistors done last evening... it was a challenging job accessing and removing them, with all the components around. But, soldering the new resistors from component side was next to impossible... moreover, i was having only 1/2 watt resistors, the pitch won't match.
I managed to pull it off like this, of course with Aniket's consent... it was too late to reassemble the amp
I can still see spillover of flux at several joints on the PCB. Use IPA to clean it off or check with Aniket how to do it more professionally
 

hydrovac

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Repairing / changing components on a double layer PCB is a pain in @$$. U need proper tools and a helping hand too to pull out the parts/components. Apart from a good soldering Iron, Desoldering Pump is a must.
sadik baba,
I was trying to emphasize on something achievable in DIY...
you interpret a challenging job is a pain in your whatever... i presume you are not a true DIY spirit. Can you please indicate what proper tools are needed, what is a good soldering iron and why de soldering pump is a must?


I can still see spillover of flux at several joints on the PCB. Use IPA to clean it off or check with Aniket how to do it more professionally
Kannan macha!
i think it's not wave soldering where you can still (have you seen it earlier also) see a spillover, poor Aniket must have done it manually. I have clearly mentioned, what resistors i have changed... what joints other than these have you noticed?
BTW it's splutter owing to usage of prehistoric flux.

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sadik

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sadik baba,
I was trying to emphasize on something achievable in DIY...
you interpret a challenging job is a pain in your whatever... i presume you are not a true DIY spirit. Can you please indicate what proper tools are needed, what is a good soldering iron and why de soldering pump is a must?
...
Bro I am sorry if you got hurt by my words, believe me it was just a description for changing the components in a double layer PCB, my intention was not to hurt you. What i meant to say was, even if we pull out the component from PCB, clearing the left over soldering inside the hole is very hard task unless you have de-soldering pump. It is even more hard if someone has to pullout component like IC with so many pins from a double layer PCB

Good Soldering Iron was not proper word to be used. I should have said high watt soldering iron.

Once again Sorry Bro.

Sadik
 

spirovious

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Bro I am sorry if you got hurt by my words, believe me it was just a description for changing the components in a double layer PCB, my intention was not to hurt you. What i meant to say was, even if we pull out the component from PCB, clearing the left over soldering inside the hole is very hard task unless you have de-soldering pump. It is even more hard if someone has to pullout component like IC with so many pins from a double layer PCB

Good Soldering Iron was not proper word to be used. I should have said high watt soldering iron.

Once again Sorry Bro.

Sadik
Soldering parts on new PCB is really fun.Removing parts need patience.If not done properly ,then chance of breaking PCB tracks/pads are more which already done by me :).Removing flux with IPA is also not easy as flux part just flows below or over other parts.May be for same reasons ,diyers are buying 2 PCBs in group buys.One for testing/modds,other for final product.
Just sharing my little diy experience.
 

stefan

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Soldering parts on new PCB is really fun.Removing parts need patience.If not done properly ,then chance of breaking PCB tracks/pads are more which already done by me :).Removing flux with IPA is also not easy as flux part just flows below or over other parts.May be for same reasons ,diyers are buying 2 PCBs in group buys.One for testing/modds,other for final product.
Just sharing my little diy experience.
I use a cotton bud to remove flux, cheap and easy, de-soldering pumps and de-soldering wicks are always worth keeping on hand.
 

flat_listener

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Maybe I can contribute something here... don't know... maybe I'm misunderstanding.
The thread started out on the topic of DD amp build and along the way folks started discussing de soldering, without OP participation.

Sometimes it's not a high jack but an evolution of the conversation... Sadik was totally innocent in my view of the matter... he offered his apology.

But if it doesn't bother anyone :), I would like see this thread continuing its "mission". hydrovac... Please, can we continue and see what will be the final result.

I don't want to get into a lengthy discussion on this, so I'm just going to state my opinion once again and maybe we'll just agree to disagree.
Can a mod move the off topic out of this thread...
 

hydrovac

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OMG! i was away only for a couple of days and a lot has been happening here.

Bro I am sorry if you got hurt by my words, believe me it was just a description for changing the components in a double layer PCB, my intention was not to hurt you. What i meant to say was, even if we pull out the component from PCB, clearing the left over soldering inside the hole is very hard task unless you have de-soldering pump. It is even more hard if someone has to pullout component like IC with so many pins from a double layer PCB

Good Soldering Iron was not proper word to be used. I should have said high watt soldering iron.

Once again Sorry Bro.

Sadik
Firstly, my intention was not to seek an apology from you Sadik... i was in the process of trouble shooting the module and was expecting suggestions in that direction.
Secondly, we are all hobbyists having varied interests and with different techniques... i rely more on my skills, than i depend on tools.
I'm sorry... I wish I’d thought of your feelings as well.


I can still see spillover of flux at several joints on the PCB. Use IPA to clean it off or check with Aniket how to do it more professionally
Same here Kannan, you are fully aware the module came as CBU... there was no other soldering done by me except changing the resistors on out put devices.


Maybe I can contribute something here... don't know... maybe I'm misunderstanding.
The thread started out on the topic of DD amp build and along the way folks started discussing de soldering, without OP participation.

Sometimes it's not a high jack but an evolution of the conversation... Sadik was totally innocent in my view of the matter... he offered his apology.

But if it doesn't bother anyone :), I would like see this thread continuing its "mission". hydrovac... Please, can we continue and see what will be the final result.

I don't want to get into a lengthy discussion on this, so I'm just going to state my opinion once again and maybe we'll just agree to disagree.
Can a mod move the off topic out of this thread...
I appreciate your imagination and creativity @flat_listener... you have given it a dramatical new twist.
The thread is very much on its original topic, no need to move any post... a little spice added to enhance the taste of broth.;)

will post updates soon.

...
 

Sanjeev Kumar

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Bro I am sorry if you got hurt by my words, believe me it was just a description for changing the components in a double layer PCB, my intention was not to hurt you. What i meant to say was, even if we pull out the component from PCB, clearing the left over soldering inside the hole is very hard task unless you have de-soldering pump. It is even more hard if someone has to pullout component like IC with so many pins from a double layer PCB

Good Soldering Iron was not proper word to be used. I should have said high watt soldering iron.

Once again Sorry Bro.

Sadik
U are too humble in admitting your mistake.
 

Beast_of_burden

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Hydro,

Amazing to see this level of DIY. Is the Elcom EMI filter effective? I see Elcom have a range of products including a power cord with inline filter. Can you let me know where to source and pricing?

Best regards
 

hifiramr

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Yes Elcom EMI filter are very effective and they keep hi quality on there products
 

hydrovac

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Hydro,

Amazing to see this level of DIY. Is the Elcom EMI filter effective? I see Elcom have a range of products including a power cord with inline filter. Can you let me know where to source and pricing?

Best regards
This is a fantastic Indian product... definitely worth your money. I used them in many DIY projects, never failed me.
You can either buy online or from these dealers.

Texonic Instruments
Amar Radio Corporation

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Beast_of_burden

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This is a fantastic Indian product... definitely worth your money. I used them in many DIY projects, never failed me.
You can either buy online or from these dealers.

Texonic Instruments
Amar Radio Corporation

...
Thanks Hydro. I will have to visit Amar Radio, don't find everything online. There are some products listed on Amazon though.
 

hydrovac

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I've built Plenty of lower powered MOSFET/Bipolar amps between 60-150watts. over the years, but only one that was 300+300 watts per channel. (200+200@8/310+310@4)

Two mono boards and a massive toroidal transformer and quad banks of MJ15003/4 outputs all in a 3 unit rack-mount aluminum case- heat-sinks out at the back. Space in the middle for the 4mm bananas and RCA jacks, power lead and fuse- very reminiscent of the Adcom GFA-555 aesthetic.

This is it! now i got a replacement... DD 200 Watt AMPLIFIER module... a decent VFM power amp you can build.
The DD is exactly the sort of easy all in one pack for a DIYer, when you need a HQ stereo / 2 channel amp, IMO. I have been listening to it extensively, and trying out various speakers over the lock down period... in the following order:

(these are my own)
Boston A26
Dali Concept 2

Last week I pinged Shravanth (Eight Audio) to borrow his Bookshelf spkrs for audition... he was kind enough, to personally drop them at my place.
@captrajesh and I had a listening session of PLATINA B17.

1590148056061.jpeg

1590148074103.jpeg

Just hooked up the Satori Ara BE, planning a session tomorrow... depends on captrajesh's time and convenience.
will update later.

1590148739563.jpeg

1590148756778.jpeg

1590148767377.jpeg

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