It's my AD815 headamp

[Kochkurov Maxim]

It's my new AD815 headamp

 

[Kochkurov Maxim]

Schematic

 

[Professor]

À òàêèå ïëàòû âû ó íàñ äåëàåòå? )) âñìûñëå, â Ðîññèè?

 

[Kochkurov Maxim]

Äà, äåëàþ, â íàëè÷èè èìåþòñÿ 10 ïëàò ïîä ýòîò óñèëèòåëü. Áîëåå ïîäðîáíî òóò

http://www.vegalab.ru/forum/showthread.php?t=5842

 

[earsandeyes]

Maxim,

Can you ellaborate on your headamp. Do I understand from your russianspeak webforum that there has been a "groupbuy"?

regards,

E&E

 

[Russ White]

Now thats what I call progress. Great work!!! Lets see how long before this catches the ire of the "AD815 gate keeper". After all he used it first, and he requires his permission. Just kidding.

Very well done ciruit I like the servos and the SMD layout. Excellent execution. A real insipration.

Thanks for sharing. I am sure it is a great headamp.

Cheers!
Russ

 

[veteran]

Great work Maxim! I like the PS section.

I'm listening to something similar and AD815 is a very good amplifier for high(er) impedance headphones.

DC Servo is a must for AD815 ARB version. I have got about output
300mV offset voltage without it . Trough hole is better but it's hard to find.

AD815 is a current feedback amplifier so feedback resistors values should be keep as low as possible.

And what with the clik and pop noise on startup and turn off?

An externally hosted image should be here but it was not working when we last tested it.

This is another nice current feedback amplifier. This time from Linear

An externally hosted image should be here but it was not working when we last tested it.

 

[peranders]

Mr. Maxim, a very nice looking pcb.

Have you seen my QRV-07? Similar design but I have used TPA6120 instead.

I notice at the right phono connector that you have a "meander" trace. Why is that?

Do you have a groundplane on solderside?

 

[Gcollier]

Excellent job! This is a very nice implementation of this super copyrighted registered trademarked, all rights reserved current feedbacck opamp (he he I couldn't resist) The PCB design is nice and professional! How does that servo seem to handle the DC offset across the entire range of the pot?

G.

 

[Professor]

À ñêîëüêî áóäóò ñòîèòü äâå ïëàòû è íàáîð äåòàëåé ïîä íèõ ?

 

[peranders]

"But two pays and collections of details under them will how much cost" said http://babelfish.altavista.com to me. Didn't tell me any particular

Mr. Professor, english is the main language here but if you have some problems with you could always try Altavista.

A hint to everybody else who want to read the russian forum, use Altavista for this also, works rather good, much better than french

 

[Kochkurov Maxim]

A cost of 1 printed-circuit board without the components is 700 rub. for Russia and 25 Eu. for other countries . I sell only PCBs and don't sell other components for this amplifier

 

[Kochkurov Maxim]

I notice at the right phono connector that you have a "meander" trace. Why is that? Do you have a groundplane on solderside?

A purpose of meander is alignment of the stray capacitance of the input circuits in both channels. Actually it does not influence to sound (I don't hear any difference), but I made it only as decorative element. This PCB has a split groundplane on bottom layer

 

[peranders]

Good you say it didn't make any difference. 1 cm2 copper on both sides makes a 3 pF cap and you have a trace over a groundplane it become even less.

 

[peranders]

Mr. Maxim could you contact me please or switch on your email button?

(Your email address is hidden as long as you don't answer any emails. It is spamsafe.)

 

[earsandeyes]

I would be interested in a board.
Maxim, please send me an PM (personal mail, see button below)

I do see that my button is gone. I have reset it but did not show-up. You can find it via my profile

Regards,

E&E

 

[peranders]

user cp => edit options => hide email address check NO.

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