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Messages - NPreston

#16
Thanks for the pointers..  I'll definitely take a look into Op amp insides too when i start catchin on!
:tu:

#17
I am kind of new to amp building and have a decent understanding of amplifying with op apms and single transistors, however I am having trouble really grasping how the differential pair commonly seen in the power section works...  I've tried reading up here and there on the net about it, but I cant say I really know how to make use of this circuit.. I kinda get it, however I dont really understand how to properly set the feedback or how to design for a specific gain etc, set dc at input, single supply vs +/- supply ect..   IN any case, was wondering if anybody knew of any good easy to follow tutorials with examples anywhere??   Something you might see in a text book with various examples??
Thanks

N.
#18
The Newcomer's Forum / Re: Just joined SS guitar!!!!
March 04, 2017, 07:33:14 AM
Thanks!!

Im pretty happy with the results so far.   but I got to give most of the credit to the speakers themselves.. 

I dont have schematic drawn up, just been kinda hacking away and learning as I go..  I'll do my best to explain..

In any case its pretty simple so far.  built on +/-15v rails using tl072 op amps and clipping back to back mosfets that have their drains connected to the gates..  gives about a 2V threshold..  in addition there are 2 stages of clipping that have lowish resistance between the mosfets and ground for a little more softness to the clipping.  all of this is inverted and buffered through another set of tl072s then fed to a common emitter config with 4 diodes in the collector side then off to a class AB configuration using TIP 142/147 and roofing hardware as heat sinks..  The last op amp buffer has a variable DC built in so I can minimize the final DC at the speakers..

Absolutely no filtering or eq yet tho..  and just a bench suppply..   Would like to build a real power supply soon as mine is pretty old and starts to drop out when I try to push any real power.. its probably 40+ years old and could probably use Caps ect..     
#19
The Newcomer's Forum / Just joined SS guitar!!!!
March 03, 2017, 08:39:48 AM
Hi,  so I have finally joined SS guitar!!!  Something I have been meaning to do for a while..   

So I have been tinkering in the basement building a crude yet functional amp (which I think sounds pretty decent so far).. 

I have a background in electronics but havn't worked in the field for a good 5 years now..  And even then I worked mostly in repair/calibration..  Design is something new to me and is quite challenging..   

anyways, I look forward to learning more and being able to share what I think I know! 

Here is a link to how things sound so far!!  Enjoy!

https://www.youtube.com/watch?v=KbZLZe0DjwI&spfreload=5