miniHRM evolution

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mat
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Re: miniHRM evolution

Post by mat »

da Geezer wrote:
bluesfendermanblues wrote:Could you post a schematic and/or photo of the amp from The clip?

Thanking you in advance :)
I 2nd that....would love to see the circuit!

G
Its the miniHRM amp with V2 12AX7 replaced with EF86. Don't have schem or layout of this version. Also I swapped few parts but did not keep record of the changes.

Also, there was a Boss digital delay on the passive loop.
mat
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da Geezer
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Re: miniHRM evolution

Post by da Geezer »

Its the miniHRM amp with V2 12AX7 replaced with EF86
Do you remember if you used "standard" (Voxey) component values on the EF86, or closer to the values on some of the 5879 pentode amps over @ the Hoffman forum?

TIA, G
10thTx
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Re: miniHRM evolution

Post by 10thTx »

How close is it to something like this? The 5879 should be on node C not D.

With respect, 10thtx
Last edited by 10thTx on Wed Feb 16, 2011 1:50 am, edited 5 times in total.
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mat
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Re: miniHRM evolution

Post by mat »

I don't remember the values but I will check them when I find the time.
mat
stiltamp
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Re: miniHRM evolution

Post by stiltamp »

Is the screen gird of the 5879 really not connected?

Manfred
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mat
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Re: miniHRM evolution

Post by mat »

Here is a (mindless noodling) clip of the guitar by itself. No after editing, just the Boss delay on the loop.

http://soundclick.com/share.cfm?id=10278064

I'll get back to the EF86 values asap.
mat
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da Geezer
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Re: miniHRM evolution

Post by da Geezer »

stiltamp wrote:Is the screen gird of the 5879 really not connected?

Manfred
That's an omission....the screen connects to the junction of the 220k & 0.1u cap, just to the right of pin 7.
10thTx
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Re: miniHRM evolution

Post by 10thTx »

Mat,

That "noodling" clip sounds great. To my ears, it is almost a tone that I would expect blending a Dumble with an overdrive Marshall.

I like how that sounds. With respect, 10thtx
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mat
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Re: miniHRM evolution

Post by mat »

10thTx wrote:Mat,

That "noodling" clip sounds great. To my ears, it is almost a tone that I would expect blending a Dumble with an overdrive Marshall.

I like how that sounds. With respect, 10thtx
Thanks Jeff :D I do like Joe Bonamassas sound alot and he uses that combination.

Here is the values around the EF86:

http://mattitee.kuvat.fi/kuvat/MTs+miniHRM/IMG_0868.jpg

Cheers,
mat
10thTx
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Re: miniHRM evolution

Post by 10thTx »

Hey Mat,

THANK you for sharing the EF86 values.

IF you are comfortable with some questions??

1) What do you have between the DPDT relay and the EF86 tube?

2) What do you have for a tone stack and level pot after the EF86?

3) Can you affirm the 6.8uf cap to ground prior to the 150k grid
resistor?

4) I have a feeling the B+ rail is drawn wrong? Which node is the EF86
connected to?

5) Any other significant errors in the schematic DRAFT?

If you want to pass on sharing the answers, that's OK too.

With respect, 10thtx
Last edited by 10thTx on Wed Feb 16, 2011 1:50 am, edited 1 time in total.
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mat
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Re: miniHRM evolution

Post by mat »

10thTx wrote:Hey Mat,

THANK you for sharing the EF86 values.

IF you are comfortable with some questions??
Sure thing 8)
1) What do you have between the DPDT relay and the EF86 tube?
470k parallel with 60p ceramic cap.
2) What do you have for a tone stack and level pot after the EF86?
No tonestack after EF86. Coupling cap after EF86 plate is 15nF.
3) Can you affirm the 6.8uf cap to ground prior to the 150k grid
resistor?
No 6.8uf cap there. 1M to ground before 150K. No trimmer.
4) I have a feeling the B+ rail is drawn wrong? Which node is the EF86
connected to?


I don't find error on the power rail.
5) Any other significant errors in the schematic DRAFT?
I have 70p treble bleed on the clean master. I have to study Your schem with more time which is something I dont have right now. You are more than welcome to ask me anything of the amp. I'll get back to You as soon as I can.

cheers,
mat
mtman5821
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Re: miniHRM evolution

Post by mtman5821 »

very nice sounds, Mat! Thanks for sharing your design with us.

Are you using the PAB on the clips? You mentioned in another thread that the clean volume is too low and the OD cleans up on the guitar, so I was thinking of trying out a single channel version of this. If you are using just PAB, the design can even further be simplified.

Thanks, Brian
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mat
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Re: miniHRM evolution

Post by mat »

mtman5821 wrote:very nice sounds, Mat! Thanks for sharing your design with us.

Are you using the PAB on the clips? You mentioned in another thread that the clean volume is too low and the OD cleans up on the guitar, so I was thinking of trying out a single channel version of this. If you are using just PAB, the design can even further be simplified.

Thanks, Brian
Thanks Brian, yes PAB is on on the clips. I did find lots of usable sounds while switching the PAB, midboost, bright switch and clean/od on and off. Nice fenderish sounds without PAB and midboost but bright on the highest position and od on.
mat
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mat
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Re: miniHRM evolution

Post by mat »

I took the clip away to avoid copyright issues.
Last edited by mat on Tue Feb 15, 2011 1:12 pm, edited 1 time in total.
mat
10thTx
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Re: miniHRM evolution

Post by 10thTx »

Is this getting closer?

with respect, 10thtx
Last edited by 10thTx on Wed Feb 16, 2011 1:51 am, edited 1 time in total.
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