Well, I think I'll go with the 5w or maybe the 15w. I some minor differences between those 2: R4&8; C15; D1, 3&4 The gain of PI stage depends on R4&8 value, because 5w requires less current of output stage it requires less PI gain in order to have same sensitivity. C4&15 - frequency...

Well, this project looks cool. I've been checkin' your website (KMG) and these Fet/micro poweramps may be what i've been searchin' for. I posted these projects (micro PA + fet PA) at the SSGuitar Forum, and I had this answer about your PA: I don't know... to me at least the MicroPA output looks pre...

Found by google
http://www.ebookee.com/Fundamentals-of- ... 13734.html
Hotfile link doesn`t work, use mirror link.

Anyway, part 1 - File not found.

Unfortunately all links dead

http://documentation.renesas.com/eng/pr ... k213ds.pdf
Input capacitance - 90pF
Reverse transfer capacitance - 2.2pF
Also transfer curve function at stage working currents (1-2mA) is very different for different (vertical/lateral ) types of mosfets.

At least compare their input capacitance

First connect the lower pin from hot to ground. In this case when you take out the jack, the input will be grounded. Second. When you have input, this mean that there is a sensitive place. Use smaller pcb track if it's possible with smaller area. Phone jack is the OUTPUT of device, in your case you...

2SK1119 is vertical mosfet, mostly designed for switch applications. 2SK216 from Renesas (Hitaci) http://ru.renesas.com/products/discrete/power_mos/power_mosfets_for_amplifier/power_mos_gen_amp/power_mos_gen_amp_root.jsp Specially designed for audio applications "Renesas provides lateral constr...

Reamping samples using Fet version of ENGL530 MOD2 as preamp. Tone controls at preamp in middle position, "Presence" and "Depth" at PA also in middle position. Digits after channel name represents "Gain" setting. http://milas.spb.ru/~kmg/files/projects/Engl530/fet/reamp...

Reamping samples through Speaker simulator V30 preamp output. Tone controls at preamp in middle position. Digits after channel name represents "Gain" setting. http://milas.spb.ru/~kmg/files/projects/Engl530/fet/reamp/SIM_V30/ Recording path: For files without "R" in name: E-MU Tr...

Reamping samples. Tone controls at preamp in middle position, "Presence" and "Depth" at PA also in middle position. Digits after channel name represents "Gain" setting. http://milas.spb.ru/~kmg/files/projects/Engl530/fet/reamp/5W4x12/ Recording path: E-MU Tracker Pre->F...

TheHog107 wrote:I was surprised in the Mesa Boogie video, there's a guy wacking the chasis into place with the wooden handle of his hammer. Nothing like the rite tool for the job.

I think that this is test for "cold " solder joints.

Use right (on your photo) contacts to pass signal to/from plug to your board in/out. Left (on your photo) contacts usually used for example for shorting input of amp to ground when no plug is inserted to avoid hum.

Some interesting videos from well known factories.
Marshall Amplification

Mesa Boogie

HiWatt UK

Enjoy

Another one test with different knob settings

Two samples of fet PA with tube preamps. Presence, Depth and Cut in clockwise position. Recording path: Ibanez RG3120TW -> tube preamp (JCM800/SLO-100) -> fet PA -> Celestion G10 Vintage 25HR -> capacitor microphone (Octava MK105 in 2 meters from cabinet) -> mic preamp -> DELTA-44 -> Samplitude v8. ...

1 and 3 are piezo type.
2 - is magnetic, coil resistance 42 Ohm.
I think it`s good as input sensor.
For output search for lower coil resistance type.

Select from "Magnetic Transducers" (without built in oscillator) such as FBMT1290 for example.
And remove part of cover and membrane as shown in video.

chicago_mike wrote:Tell me you have another compressor circuit lying around with tubes.

You can take compressor part from ampeg bass amp.
Signal path built on tubes, rectifier using opamp, control element is LDR.
http://217.119.30.118/~kmg/files/schema ... 3904H0.PDF