miniHRM evolution

[mat]

Hey mat,

fantastic sound!
Thanks for sharing your design!

How does it sound if feed the OD into the power amp of your nonHRM?

Sorry if this has already been asked (and answered).

Peace

Markus

Hi Markus,

I haven't tried that but will at the next rehearsals.. that will take place at the third of april..

[bepone]

hello to all, i have great contribution to this thread !

thanks to the mats great thread (and playing too ), last two weeks i spent some time to construct a little PP amp which have similar topology like mats, but unfortunately i finished with an PP amp notr S.E:

i tried to build something like this:

(ECC83->duble TS-> ECC83-> some penthode for OD-> and in output some tube like EL84 S.E)

i started good with ECC83 and dumble TS, but didnt have EF86 penthodes, nor EL84, but i had about 1000 TV tubes at home , and i found small PP 15W OT in basement.. so i picked two PCL86 ( 14GW8 i think in the USA) because penthode section in this tube is somelike smaller version of EL84, and triode section is like one half of ECC83..

two PCL's for phase splitter and PP output (datasheet says that will 12-14W came out)

penthode in OD is also picked from old TV , EF89 and EF80 were candidates, because i had them ( scattered everywere )
-----------------

finished an amp, clean channel with ECC83 and dumble TS was standard great, soft and rounded, but for OD i didnt have idea what to expect. but i must say,
those EF80 tube is excellent!! for soft, rounded, rocky distortion, without treble spikes in distortion! just big balls with LP in those sound (OD trimmer can go to max)

EF89 is not for use in this type of amp, because its bias (0->-40V), and this tube have something weaker , in the lifeless meaning, drive..

sorry for my bad english, and greetings from croatia!

[markusw]

Hey mat,

fantastic sound!
Thanks for sharing your design!

How does it sound if feed the OD into the power amp of your nonHRM?

Sorry if this has already been asked (and answered).

Peace

Markus

Hi Markus,

I haven't tried that but will at the next rehearsals.. that will take place at the third of april..

Hi mat,

waiting patiently for your report

Peace,

Markus

[mat]

Exellent! If possible, pleas post a clip of Your amp. I also have a small box full of odd tubes. IIRR there is a few EF80's also.

[bepone]

hello mat, it is in the process, i hope that the record will be soon,
regards, josip

[bepone]

here are first records..just raw sound from an amp which is captured with zoom h2.

not so ideal situation because we connect some nervous celestion 12" speaker from marshall valvestate amp.. guitar is fine, gibson LP.
amp has this tubes:
ECC83->EF80-> 2PCL86's in PP


controls :
VOL 6/10
BASS 4/10 ( maybe too much)
MID 2/10 (because of nervous speaker)
TREB 2/10 (-"-)
------------------
DRIVE 5/10
MASTER 7/10
PRESENCE 4/10
----------------------
http://www.soundclick.com/player/single ... D=10440612

more gain
http://www.soundclick.com/player/single ... D=10440337

--------------------------

i will appreciate comments and thoughts (i think that will tomorrow tame some bass and record with more middle and treble, and play with h2 rec positions),
regards Josip

[stiltamp]

hi bepone,

did you change any parts for the EF86 -> EF80 replacement.

cheers
Manfred

[bepone]

hello manfred,

yes, EF80 is a different tube than EF86. i look in EF80 datasheet , about recomended working point, currents, loads etc... EF80 works with bigger current than EF86 and asks for 20K anode load. so with some paper drawing and adjusting resistors, the values are:

Ub+ cca 250V
R anode - 20K 2W
Rg2 - 22K 2w
Rk - 470 ohms, bypass cap 22uF (that cap value is too big/i must tame some bass/ first will put this to 1-2uF), Rk can go to 390 ohms for changing OD character, adjust to personal taste
Cg2 cap to ground is 100 nF/400V
g3 connected to cathode
Rg1 (grid stopper)- 150K
Rg1 leak (to the ground) - 1M in paralell with OD trim pot

snubber cap - 470pF across the 20K anode resitor/ omit for more agressive OD

regards, josip

[mat]

Josip, thanks for the clips. Great potential there. I think the speaker plays big part on getting the amp to sound good. Let us know if You will try different speakers/cabinets on the amp.
To me the old Zoom H4 recorder sounded quite bad comparing to our other recording setup(SM57-Firepod-PC).

Would be nice to hear a clip of volume and gain cranked and guitar volume backed to 6 or something.

here are first records..just raw sound from an amp which is captured with zoom h2.

not so ideal situation because we connect some nervous celestion 12" speaker from marshall valvestate amp.. guitar is fine, gibson LP.
amp has this tubes:
ECC83->EF80-> 2PCL86's in PP


controls :
VOL 6/10
BASS 4/10 ( maybe too much)
MID 2/10 (because of nervous speaker)
TREB 2/10 (-"-)
------------------
DRIVE 5/10
MASTER 7/10
PRESENCE 4/10
----------------------
http://www.soundclick.com/player/single ... D=10440612

more gain
http://www.soundclick.com/player/single ... D=10440337

--------------------------

i will appreciate comments and thoughts (i think that will tomorrow tame some bass and record with more middle and treble, and play with h2 rec positions),
regards Josip

[azatplayer]

Mat, do yu find a spot that you just leave the amp in?
With all the switching these things have, im wondering if an even more simplified grab and go little guy would be cool too.
For example, the switch for the third gain stage, do you leave it in and control the amp from the guitar for cleanup? Or is the clean channel very sweet and usable?
I often find with an amp, that for all of its controls, i usually have a sweet spot for my style, and the volume is more or less the only control used.
Of course we have different guitars and sometimes strats need a darker tone than Les Pauls, so tone control is important for the individual.
I just wonder mainly, if you leave the gain stage switched in and the PAB on, generally?
Will find out soon enough, im about to start this build this week. Looking forward to it!
Don

[mat]

Mat, do yu find a spot that you just leave the amp in?
With all the switching these things have, im wondering if an even more simplified grab and go little guy would be cool too.
For example, the switch for the third gain stage, do you leave it in and control the amp from the guitar for cleanup? Or is the clean channel very sweet and usable?
I often find with an amp, that for all of its controls, i usually have a sweet spot for my style, and the volume is more or less the only control used.
Of course we have different guitars and sometimes strats need a darker tone than Les Pauls, so tone control is important for the individual.
I just wonder mainly, if you leave the gain stage switched in and the PAB on, generally?
Will find out soon enough, im about to start this build this week. Looking forward to it!
Don

Hi Don,
At home my settings vary a lot day by day. With the nonHRM build the settings seem to be same at all times but with 86-Special I'm constantly altering them. I like the chimines of the 86 clean and I like a lot of the od with all different settings.
At band rehearsals I mainly use the volume knob of the guitar to get clean/dirty sounds. IIRR volume (trimmer inside the amp) at 13:00 o'clock, bass&treble at 12:00, OD volume at 13:00 and drive from 12:00 to 14:00. Mid boost on, bright switch off.

[azatplayer]

Cheers mate. Im working on my layout today, proly start drilling and punching the chassis too. Quite excited actually!

[rogb]

Cheers mate. Im working on my layout today, proly start drilling and punching the chassis too. Quite excited actually!

Good stuff!

All my parts have arrived now, just finishing off the cab this weekend.

Any help you could give with pics of your layout would be really great.
Hope to start building on Monday and I am not 100% decided on the layout, being a recently graduated noob
I am going by the AX84 boards but with D style power and pre amp boards, if you see what I mean.

One small change will be a 500K trimmer in place of the mid resistor as I like to tweak my mids, also a parallel 6V6 socket, so I can experiment with differen tubes. Also a bias adjuster as per AX84.
Good luck mate!

[azatplayer]

Ahhh be great to compare notes!
Ive ordered trannies from Heyboer, using a 3k/5k OT. Im going parallel EL84's on mine.
Plan is to wire in separate cathodes for each EL84, and use a dpdt switch to throw in the second cathode and change primary from 5k(single) to 3k for both tubes. Give me 5 watts which i think is great for a lot of gigs i do, but also a little more grunt/headroom from the extra tube when needed.

Im still undecided on whether to go tagstrips or make a board. Theres not a lot in there but i also wanna simplify things. Mat has only 5 knobs on his amp. Where this layout thats been suggested runs 7. I like the idea of using more trimpots and internal switching, so you can mess with it, but keep the front simple. Like the bright switch, im not putting one in, will determine what is needed when its built, one less thing. Might even decide that leaving the 86' on all the tme is what I like.

Be great anyways to see the two amps come out.
What are you planning on using for speakers?

[10thTx]

Mat,

I know you're busy, but when you can, it would be important to know the accurate voltages on the EF86 tube at node C?

If 325v is accurate then another PT such as a 270FX may be needed instead of a 269EX for the single ended version 86 Special?

With respect, 10thtx