miniHRM evolution

[mat]

Is this getting closer?

with respect, 10thtx

Hi again Jeff,

I think Your schem around the EF86 is not like in the picture I posted.

Other things:

V1 coupling cap is 2n2.

Mid boost cap is 380p.

No mid pot, just 120k to ground after the .01.

PAB resistors not 22M but 20M.

Treble pot is 250kL.

Pre volume is a trimmer inside the chassis on my build.

The EH86 entrance 60p/470k (schem has 60p/470p).

After the 60p/470k there is 250p in to 470k to ground.

Also after the 60p/470k is drive pot (250kA). The signal goes to the viper while other side goes to ground and other side goes to the 1M/150k junction.

66n to ground on EF86 pin 1.

No 220k from point C.

No 220k from the OD master viper - straight to the switch.

From OD master viper there is 470p into 1MB (smooth pot). Other side goes trough 4n7 to ground. Smooth pot viper goes to side of the OD master pot (not on the ground side). This is quite like on Your schem but wired a bit differently.

Also I have a standby switch after the bridge rectifier.

Check the EF86 connections and I think we are pretty close of the same thing

Cheers,

[10thTx]

Mat,

I hope you'll be patient with me. I am trying my best to follow your directives about the schematic.

Q1: Is the drive looking correct??? If so, one could use a 500k there
I think to do the same thing?

Q2: Is that accurate that there is not a resistor there on the EF86?

Once this is accurate, I'll delete all other versions and create a layout for it.

Thanks & with respect, 10thtx

[mat]

Mat,

I hope you'll be patient with me. I am trying my best to follow your directives about the schematic.

Q1: Is the drive looking correct??? If so, one could use a 500k there
I think to do the same thing?

Q2: Is that accurate that there is not a resistor there on the EF86?

Once this is accurate, I'll delete all other versions and create a layout for it.

Thanks & with respect, 10thtx

Jeff, you have also to be patient with me I'm not very good at this. I just trust my ears and if something sounds good to me it stays. There might be some silly connections but I'll check the parts You pointed out and get back to You. Still working 12h days so it might take few days to get this finished.
I'll get back to You,

[stiltamp]

Without the resistor the EF86 works in the tirode mode.
In that case the 0.066 capacitor acts as "snubber".
I think that value is to high then.

[mat]

Without the resistor the EF86 works in the tirode mode.
In that case the 0.066 capacitor acts as "snubber".
I think that value is to high then.

I have nothing connected to pin7 of the EF86. There is 820k connected to the pin1 like on the drawing I posted.

Jeff, should the pin 7 on Your schem be pin 1 ?

This is how my EF86 is wired: http://mattitee.kuvat.fi/kuvat/MTs%20mi ... 9.jpg/full

[mat]

Q1: Is the drive looking correct??? If so, one could use a 500k there
I think to do the same thing?

The drive pot seems to be same as on mine. I don't know the effect of using 500k in there.

As in my earlier post: After the 60p/470k there is 250p in to 470k to ground.

Feel free to ask more

[10thTx]

Mat,

You're a great guy ....... thanks for sharing your information and for all the patience you've extended in helping edit this for the forum guys.

Sure do appreciate the help. I marvel that we're on different continents and can work on this together. How cool is that!! Now if you could just send some of your great guitar ability my way ......


I think we're probably getting pretty close at this point? I went back and deleted all the other drafts of the schematic that I posted.

Any other revisions? Again, I'll draw up a draft layout once the schematic is edited and OK'd.

Best regards, 10thtx

[mat]

I marvel that we're on different continents and can work on this together. How cool is that!!

The power of internet is quite amazing. I would not have built amps/pedals without the net and gentlemen like You

I went quickly trough Your schem - did not have much time. Here is the latest edit:

http://mattitee.kuvat.fi/kuvat/MTs%20mi ... d.GIF/full

[10thTx]

OK, here is the latest edit along with a layout to edit if needed.

Thanks again for your patience and willingness to share.

with respect, 10thtx


Editable versions here: http://www.el34world.com/Forum/index.ph ... #msg101781

[mat]

OK, here is the latest edit along with a layout to edit if needed. Thanks again for your patience and willingness to share.

Jeff, thank You for making the schem and layout. Easier for me to further develop the amp from now one.
I've learnt so much cool stuff from this forum so I'm more than happy to give something back

[rogb]

Terve Mat, mitä kuuluu? I am quite often in Helsinki so I picked up some words:lol: (mutta ei slangi lol)

Wow what a great amp! Top playing and tones too. Love the 339. I'm just starting a new 22w 6V6 build and now the miniHRM is definitely going to be built too. I think your development will be very popular with folks on here.

What a fantastic job you have done here, together with online collaboration from the TAG.

I saw the pics of your combo. What size chassis and speaker did you use please? I am building my 22w on a Dlite size chassis but this could go a little smaller, I guess.

I will certainly build a lightweight pine combo cab for the miniHRM (or Mat-amp HRM )

Voi hyvin
Roger

[mat]

Terve Mat, mitä kuuluu? I am quite often in Helsinki so I picked up some words:lol: (mutta ei slangi lol)

Wow what a great amp! Top playing and tones too. Love the 339. I'm just starting a new 22w 6V6 build and now the miniHRM is definitely going to be built too. I think your development will be very popular with folks on here.

What a fantastic job you have done here, together with online collaboration from the TAG.

I saw the pics of your combo. What size chassis and speaker did you use please? I am building my 22w on a Dlite size chassis but this could go a little smaller, I guess.

I will certainly build a lightweight pine combo cab for the miniHRM (or Mat-amp HRM )

Voi hyvin
Roger

Terve Roger,

Thanks for Your kind words !

Don't remember the exact size of the chassis (am at work), about 30cm wide so about 12 inches. The speaker on my combo is Weber 1265 ceramic that I don't like at all. The clips are recorded with 2x12'' Delta Pro cabinet that in my opinion is great match with this little amp. I would try to find a speaker that colors as little as possible the sound of the amp.

The EF86 seems to be a quite sensitive tube so I would not recommend to build a combo around it. I've installed rubber grommets to the tube socket and am planning to put extra weight to the tube shield of the EF86.

Good luck for Your 6V6 build

[stelligan]

Cool playing and tones, Mat. Thanks to mat, 10thTx, and all involved for the hard work on this - it looks like it would be a cool build. Sounds great.

[mat]

Cool playing and tones, Mat. Thanks to mat, 10thTx, and all involved for the hard work on this - it looks like it would be a cool build. Sounds great.

Thanks stelligan!

I've been digging Your sounclips very much. Nice personal touch on Your playing !

[rogb]

Terve Mat, mitä kuuluu? I am quite often in Helsinki so I picked up some words:lol: (mutta ei slangi lol)

Wow what a great amp! Top playing and tones too. Love the 339. I'm just starting a new 22w 6V6 build and now the miniHRM is definitely going to be built too. I think your development will be very popular with folks on here.

What a fantastic job you have done here, together with online collaboration from the TAG.

I saw the pics of your combo. What size chassis and speaker did you use please? I am building my 22w on a Dlite size chassis but this could go a little smaller, I guess.

I will certainly build a lightweight pine combo cab for the miniHRM (or Mat-amp HRM )

Voi hyvin
Roger

Terve Roger,

Thanks for Your kind words !

Don't remember the exact size of the chassis (am at work), about 30cm wide so about 12 inches. The speaker on my combo is Weber 1265 ceramic that I don't like at all. The clips are recorded with 2x12'' Delta Pro cabinet that in my opinion is great match with this little amp. I would try to find a speaker that colors as little as possible the sound of the amp.

The EF86 seems to be a quite sensitive tube so I would not recommend to build a combo around it. I've installed rubber grommets to the tube socket and am planning to put extra weight to the tube shield of the EF86.

Good luck for Your 6V6 build

Thanks Mat, I think I'm going to do this one first, but I will order most of the UK hard-to-find parts for both at the same time from Mouser etc.
I found a chassis 12"x8x2 at Bluebell and I will try it in a combo,( even against your good advice )with a 10" Emi Lil Buddy.
I can try to isolate the EF86/chassis if there are problems.
It will be great for a small jam I play which is virtually acoustic, no drums, just guitars and bass, where good tones are appreciated but not high levels. Folk actually sit and listen here

The Hammond 269EX seems quite hard to find over here, does it come in a Euro voltage?

regards
Roger