LDR Active Preamp - does it exist?

Great idea, except gain is exactly what he's looking for.

Using Lightspeed, I can get the sound level at average 90 dB with high sensitive speaker 98 dB. The dial is near to max, position between 2 PM - 3 PM. Low volume tracks are the problem.

In anycase, I would like to optimize our system using the amps that I have in hand. It seems that these amps are not best choice. The main reason I am going with 845 output tube is the power 27 Watt that 300B SET can not provide. It seem low sensitivity defeats the purposes.

The Truth is an interesting concept. It does not seem to be popular in audiophile community.

Nguyen787 if you feel like you need to move off of the Lightspeed I`d be very interested in it.
Regards
Steve

Nguyen, the amps 4v sensitivity is the problem, try this, email the manufacturer and ask is there any way of getting the amps sensitivity to 2v or even 3v will do. It may be a simple thing like change the input tube for a higher gain one.
If not you could get someone to build this simple buffer that has gain, parts would be around $10 http://www.diyaudio.com/forums/attachments/analog-line-level/341197d1365395103-preamp-buffers-simple-idea-buffers.gif

I Just looked at you input tube 6SN7 it is a very low gain tube of 20. A tube tech should be able to reconfigure this for a higher gain tube of say 40 or so with a different input tube.


Cheers George

Thanks George. I asked Grant Fidelity but did not get the answer I want to hear.

It is suggested that the amp Shuguang S845MK need to match with preamp Shuguang S200MK. The preamp spec is kinda freaky:

Input impedance: 100kohm
Input Power Voltage: ≤150mV
Output Voltage: more than 3V, maximum 10V
Output impedance: less than 10k ohm

Duc