Don Sach's pre amp

for the record the circuit used in the SP-14 is a direct copy of John Broskie‘s Aikido as published in the Tubecad Journal. This circuit has since been used by Don Allen. No credit has been given to Mr Broskie for using his design by either constructor.

Pesky_Rabbit,

From a derivative stand point, Don Sachs has acknowledged that the inspiration for his preamp came from Roy Mottram's SP-14 preamp. Indeed, Roy mentions Don in his website so their relationship is very solid.  http://www.tubes4hifi.com/SP14.ht   Frankly, 90% of front end gear is a derivative design from earlier designs.

Don currently is a devotee of these 6SN7 tubes: Linlai E-6sn7 tubes.  I just ordered a quad of them. The quad cost ~$375 plus $55 for shipping from China.  

I am aware of him crediting the SP-14, but someone with his knowledge of electronics would also be acutely aware that circuit is a straight copy of an Aikido. Given that this topology is well known, has been published in great detail, and has a name and an owner who supplies pc boards and kits for its construction I think it is rather disingenuous of him not to recognise it as such. By crediting the SP-14 as the inspiration for his circuit he sidesteps the issue completely

Pesky wabbit I agree with you that credit should be given to John Broskie for the buffer stage in the sp14 and the Don Sachs preamp.