Hey I thought I would give you an update on this.
I tried numerous tonestacks both before and after the 386.
SO this is after many trials.I am very happy and have played it alot it makes a great clean boost EQ,and can get clipping in a variaty of ways.
I have been using it like a pedal in front of my other amps and even my wife commented on how good it sounded(she likes heavy music)It sounds insane overdriving my Valve Jr or 18 watt with it.
It is much more versatile than before and so many shades of rock and metal are available.
The only downside now is the knob count I have run out of room for more,as I used a 25k for the 2 diodes to ground and added a 100K in series to the 1m on the OD channel so that its easy to set the 100K for classic rock then dial up the 1M pot for heavy sounds,And also I have a 47uf on pin 7 of 386 that isnt shown.
Here is the latest schematic - pre-amp only- note low power 386 this time and other subtle changes.http://i419.photobucket.com/albums/pp276/Bry928/SolidState%20Amps/12Watt-TDA1519B%20build/PreAmpAsPedal.jpg
Also I asked a member at DIYstompboxes to draw a PCB layout, it isnt verified yet but it is here http://www.diystompboxes.com/smfforum/index.php?topic=79693.0
Thanx to Sean K for that layout.
I have been using 9V battery and with the master volume it works fantastic, swapping in the lower power 386 helped too.
I really would like to expand it to two actual channels each with its own TMB tonestack.
But then I'm thinking a bipolar V supply would be better too along with mosfet switching so
I will make that another preamp altogether and call this one good.
Except I do plan on adding a rotary switch with a couple of different diode options including a mosfet diode clipper.
I hope someone finds this useful I have spent months working on it finding what sounds best to me.And am very pleased with it.

You might have better luck asking at DIYstompboxes.com
I am not familiar with that pedal or any mods for it,but some one over there probably is.

Wow thats really nice Serg.
The cabinet reminds me of the cab for my 18 watt Marshall.
The first one was for testing,I have one in the garage for a year now sanded and wetted 6X just cant decide on the stain to finish it up so it sits wrapped in plastic.
Its so nice when you can say you built the whole thing cab and all isnt it?
Post some sound clips when your finished if you can.
Great work Serg  :tu:

Quote from: J M Fahey on October 12, 2009, 04:08:08 PM
Congratulations.
Very nice, very professional.
Please post the preamp, when you have it.
Juan Manuel Fahey.

Yeah what he said.

Thank you,
Its pretty loud with a good spkr (like 2x12" with 99db SPL)
Its just loud enough to jam with my friend on drums,but he can easily play over me with out trying.
I built that for a friend as a practice amp.
But for a small venue I think a 30-40 watt SS amp would be better.Like a single LM3886 for example.
My 40 watt Crate was loud enough but still some heavy handed drummer could still play over it...
If I were to do it over again I would probably use one of the TDA20XX chips.
The tda1519 was only .79 at Apex Jr and I was already ordering stuff for my LM3886 build so I got a few of them as well for 12V supply use.

Phatt the data sheet for ECC99 lists a quad for 10 watts in PP or 2 for 5 watts a single ECC99 is 2.5 watts in self split PP on the Firefly.
This is a new tube developed by JJ for use as a headphone amp as a driver in an amp like 300B or for low wattage PP designs.
It has been getting rave reviews for audiophiles and guitar gear junkies alike.

Here is a better way of expressing what I wanted to say before.
If your guitar has a signal of 1V and your pre-amp amplifies it by a factor of 10
Then your last stage- a voltage follower needs to have a gain of .1 to bring the signal back down to 1volt to input your chip amp  :tu:

How is your project coming ?
I missed this thread somehow,but I had the exact same idea.
Re-amping a Firefly type amp with a lm3886.
I recently heard a Firefly that used ECC99 for the output tube and it was SO much better sounding than the 12AU7 version the guy built it out of.
But the ECC99 is a new tube and there isnt much on the web about it.
I would love to see a schemaitc of a 10 watt PP amp using 4 ECC99 tubes(sorry off topic)
Also I like the idea of the NEO spkr.
I want to build a light weight amp using toriodal trannies and a NEO spkr,aluminum chassis,
And Pine cab shouldnt weigh much like that.

How about a schematic Phatt?

I am gonna take a stab at this since I want to do the same thing.
Please guys correct me if I am wrong.
Mensur mentioned in his hybrid build that you need a Voltage follower to reduce the impedence,I asked if a cathode follower would work he said yes.
But I worry too with the plate voltage in my preamp being around 300V at the last stage,
about coupling that to a SS chip amp.
The Alembic F2B seems to have the output taken directly from the plate of the last triode.
And at Alembic they said they run them into McIntosh amps so IDK.
I now think a voltage follower using a mosfet with the gain set inverse and porportional
to the accumilated gain of the pre-amp is what is needed to make one work.
Meaning if the total gain of the preamp is 100 you would have the follower attenuate the signal by dividing by 100 so 300v divided by 100 would be 3volts out? HMMM still too much...
But you get the idea I just dont know how to do the math to show you.
Just set the gain of the voltage follower so it only has 1-2volts P-P at its output.
I guess this could be done with a tube too,or just get a mosfet rated higher than your max B+ voltage.
SO RG ,JM ,Teemuk, Armstrom and crew am I close?
Or should I delete this post?

Cool this one is 100watts @4ohms they state "ideal for guitar or instrument amp"
http://store.qkits.com/moreinfo.cfm/HSVM100
only 27$ For the heat sink and power supply (from Apex Jr) your looking at another 40$
plus the pre-amp ,spkr and enclosure.
It could be done for less than 150$

They have a 30-40watt amp that around the same price a little cheaper but it includes the heatsink and APexJr has a supply for it for about 10$
That would make it in under 100$ with a homemade enclosure and a decent 12" spkr.

Hey Armstron thats excellent.
Does it come with everything? except the power supply of course but the IC PCB and caps and resistors are they all there at that price?
If so that would be ideal for Slim Blues Boy

GREAT
I look forward to the updates.
Very nice looking from the front,lucky you having JM come over and help. :tu:

SWEET,
You should post this at DIYstomboxes too.I bet the guys there will get a kick out of it.
Thanx for sharing.

Thanx for the update Joe.
Wouldnt be OK to use 4amp diodes X4 instead of those 25amp bridges?
I'm curious cause thats what I was planning on using with those trannies along with snubbers or is that too low a rating?
And are snubbers unnecessary ? I noticed you didnt use any.

Edit OK I went in the garage and looked and those are only 2amp trannies so I think 4amp diodes will be fine.
But what do you think about adding snubbers?