Preamp for the leach amp (2x120)

[roger-k]

Soon I am finnish with my leach apm and I am looking for a good preamp.
I have made a PCD-drawings over the "HIFI-Preamp" (project 97) from Elliot Sounds Products (http://sound.westhostcom/project97.htm)

Is there anyone who have som experience with this preamp?
Or maybe I should made another preamp?

[roger-k]

I'm sorry for the smile.
I didn't know what it means.

I am a new user of diyaudio.
I hope somone can help me to pick
a good preamp.

[Praudio]

Why not a passive one ! no low cost preamp can't beat a passive.
A bit less dynamic,but much more natural sound. Use a top Vishay quality resistor in series and go with a black beauty or noble across, or a L pad.

[roger-k]

I want to have tonecontrols on the preamp. Maybe the gain will be to low if I use a passive with tonecontrols?

[fab]

Roger-k

With a good pre-amp, a good amp and reasonably good speakers, you should not require tonecontrol (except for the low frequency compensation cause no speaker in the world can reproduce 20 Hz at 0 db!). So a simple variable loudness may be required to have a more natural sound ay low listening sound levels (it can also be used to compensate for bad recordings). For the pre-amp try to avoid opamp circuits but use a discrete circuit with high output current.

[rickcr42]

http://users.ece.gatech.edu/~mleach/...b77article.pdf

[roger-k]

Many thanks to you all!

I like diyaudio.com more and more for every time I visite it.
It is the best audioforum on internet.

I want to make the ALEPH P1.7 form Pass Labs
(http://web.vip.hr/pcb-design.vip/aleph-17.html)
or the preamp in PDF-file (constructed by W. Marshall Leach)
I am not shure yet.

[fab]

The Pass and Leach designs are quite different. The Pass uses super-symetry and the Leach (if this is the PDF received in preious post) has no symetry at all (don't get me wrong I do not judge symetry or not).
The Leach PDF includes a phono pre-amp, tonecontrol, center channel, etc. but from what I understand the pre-amp for line level signal consists of only the right part of fig 1. If that is the case, the Pass is surely a more "advanced" design than the Leach one. Of course, it is only my opinion.

[roger-k]

I am still confused because the schematic in fig 1 is little simplified.
In the same PDF-file ther is also two completed schematic over the leach-preamp, one with tonecontroll and one without.

Is there sombody out there who have make the ALEPH P1.7 form Pass Labs?

[rickcr42]

the confusion in the leach preamp pdf is due to the added update pages with a jfet front end and monolithic regulators instead of the zener shunt regulators.

The original circuit is for a simple class-A discrete opamp and fills your need for a tone controls plus it is designed by the same person that designed the amp you are using.

read the article carefully and and once you understand it you can modify the line stage gain/EQ to suit your needs