That reason was already in my mind
Why I asked you regarding C4 is , I ordered all the components and ques which I did forget to order ; Yes C4 but I've enough 470µF caps
Thiago,
You are absolutely correct! Many small signal transistors will work in this amp, but variations will change the harmonic profile more or less in unexpected ways.
The big issue is the voltage rating. We have 42V rails, so we need to have Vceo figures on all these devices higher than 85V and preferably 100V or even 120V. The A1381 is rated to 300V and 150MHz; far more than we need. The 5401/551 are rated to 160V and 150MHz too, but BC557/547 are rated max at 65V and 300MHz - not adequate in this role. Some transistors are noisy too, so you have to avoid them as well.
Hugh
You are absolutely correct! Many small signal transistors will work in this amp, but variations will change the harmonic profile more or less in unexpected ways.
The big issue is the voltage rating. We have 42V rails, so we need to have Vceo figures on all these devices higher than 85V and preferably 100V or even 120V. The A1381 is rated to 300V and 150MHz; far more than we need. The 5401/551 are rated to 160V and 150MHz too, but BC557/547 are rated max at 65V and 300MHz - not adequate in this role. Some transistors are noisy too, so you have to avoid them as well.
Hugh
Just want to add, that PCBway actually sent me 11 PCBs, instead of 10 pcs (as ordered). Guess they had some extra space, and didn't want to waste the material. So not that sterile perhaps
In fact I have only good things to say about them - especially given the price level. But yes, be sure to check and validate your Gerber files before ordering. I gladly accept that responsibility..
Just want to add, that PCBway actually sent me 11 PCBs, instead of 10 pcs (as ordered). Guess they had some extra space, and didn't want to waste the material. So not that sterile perhaps
In fact I have only good things to say about them - especially given the price level. But yes, be sure to check and validate your Gerber files before ordering. I gladly accept that responsibility..
Hi jvhb,
I received your PCB today+1845. I might add, they actually look different in a cool way.
Nice and thanks so much again.
Phunk did a very nice job on designing.
Ofcourse thanks to Ranch32 and Hugh.
Regards
Prasi
Hi jvhb
I received the PC boards yesterday evening. Thank you very much!
It was delivered very fast, usually Canada post is very slow on delivery.
One more time I appreciate it and thank you from the bottom of my hearth.
Hi jvhb
I received the PC boards yesterday evening. Thank you very much!
It was delivered very fast, usually Canada post is very slow on delivery.
One more time I appreciate it and thank you from the bottom of my hearth.
Yes I agree , Canada post is very slow. PCBs sent to Canada get delivered very very late.
regarding 10 versus 11 PCB , most Chinese manufacturers do that. I have shifted over from PCBway to esasyeda....easyeda has been giving me 11 PCBs consistently...
2$ for less than 100mm x 100mm even if its 99.5x 99.5...OR so....
so total including shipping is 12 USD for 11 perfectly working PCB.
PCBway is 17-18 USD...Duh!
So go ahead DIYers and use the opportunity of 2 USD for 10+1 PCB +shipping...just google easyeda
regards
Prasi
....easyeda has been giving me 11 PCBs consistently...2$ for less than 100mm x 100mm even if its 99.5x 99.5...OR so....
so total including shipping is 12 USD for 11 perfectly working PCB.
PCBway is 17-18 USD...Duh!
So go ahead DIYers and use the opportunity of 2 USD for 10+1 PCB +shipping...just google easyeda
regards
Prasi
Gooday all,
Can some plse help. According to the circuit that I have used there is no resistor in parallel with C2(220pf). In some of the other builds there are a 22k resistor in parallel with C2.What will be the effect soundwise be by adding the resistor across C2 ? Thanks for helping !
Can some plse help. According to the circuit that I have used there is no resistor in parallel with C2(220pf). In some of the other builds there are a 22k resistor in parallel with C2.What will be the effect soundwise be by adding the resistor across C2 ? Thanks for helping !
Attachments
Gooday all,
According to the schematic from Hugh the negative from capacitor C7 must be connected to the anode of D7. In both Prasi's and Thiago's circuits the negative goes to the cathode of D7 which is wrong. Did anybody try to change it ? If so,Were there a difference in sound ?
According to the schematic from Hugh the negative from capacitor C7 must be connected to the anode of D7. In both Prasi's and Thiago's circuits the negative goes to the cathode of D7 which is wrong. Did anybody try to change it ? If so,Were there a difference in sound ?
Attachments
Yes, these schematics above is correct. I have build boards from Thiago and these are not correct. This schematic of yours is not correct either. Post 1114
Very simple quasi complimentary MOSFET amplifier
Very simple quasi complimentary MOSFET amplifier