Anyone know what the "tiny terror" circuit is?

[gndboy]

Fat Gaz has it right

The unusual position of the R-C tone control FOLLOWING the driver/phase inverter is quite interesting. This is a thick-sounding amp at low volume level, which I believe was the design goal. I have two, and want to experiment with the old tubes. Thus far (and after the first inevitable try at cranking) I am quite happy with this box. It really performs well over the control variations. Expecting an AD30 will lead to frustration.

[Thomeeque]

Thanks Thomeeque, I think on my construction it is not needed. I have metal chasis with both transformator on the top. Each is on other side and have position 90 degree each. All resistors and capacitor is bottom chasis. Both ECC83 is on metal cover. I send there later link picture of my construction.
Is not to nice, like your amp
Here is my pictures:
raj?e.net | místo pro va?e fotografie

2xEL84
2xECC83
1XEZ81
1XLK199 - Stabilizator for anode voltage preamp ECC83

Well, mine is maybe prettier, but imo more gutarists would pick yours at first sight! ... OK, those guts are bit too messy

You can have some electromagnetic feedback between two components/wires - as a lot of them acts like small antenna and/or small receiver and tube circuits are very sensitive circuits. Try to get it into the oscillations, then listen to it and lightly tap to individual components by some non-conductive long-enough (to keep your hands in save distance from high voltages inside) stick (e.g. by wooden skewer = špejle /CZ term/ ) - if it will detune oscillations somehow, you have maybe found problematic area.

Good luck (you will need it )!

T.

[Thomeeque]

It seems that there are different layouts in internet for this amp.
http://www.trinityamps.com/ForumGall...out_v.1.11.jpg
and
http://music-electronics-forum.com/a...ror-layout.pdf

Tiny_Terror_Layout_v.1.11.jpg contains at least two flaws, be careful! By some funny coincidence exactly Yesterday I've talk about it at different forum so I can quote myself

...
BEWARE: If you will google for OTT clone info, you will soon or later come across this layout, it is very often reffered - it contains at least two flaws (first stage is not grounded and master volume dual pot is wired in wrong way). And I've already seen some redrawn schemo, where some original component values were wrongly interpreted. My point is: if you would plan to use such sources, always double-check with original AdmiralB's schematic, it is verified.
...

Second (by another funny coincidence ) comes from this very thread, just few posts below, and should be verified since gtrbryan says it's the layout he has used in his successful build

T.

EDIT: But these are both DIY layouts! If you are looking for original OTT layout to find the point where you should cut the PCB trace, these won't help you - use the schemo, you can't miss it - it's the trace leading from central lug of second "half" of dual GAIN pot to the 47nF capacitor (it's the only place, where the central lug of some pot leads to some capacitor and nowhere else).

[benjy]

Hi, benjy!

Basically they mean probably this:



Unfortunately the statement "But it does come after all of the the preamp's tone-shaping and gain circuitry." is IMO not 100% correct - Tiny Terror uses even overdriven PI (PI = Phase Inverter) made by second ECC83, to achieve more distortion (it's one of it's most unique features). So you cannot get full preamp distortion of OTT into FX loop this way (and frankly there's no any other reasonable way).. but you can try this, maybe it will work for you (it depends on the way you use your OTT).

Sorry, I have to leave for now..

T.

Hey thanks a lot, I'll try this.
Several people say that they mod the TT with FX Loop and it's working awesome, so I hope they did it this way.
I'll post my results later.

[benjy]

FX Loop

Ok, the FX Loop is ready and working. I did it this way and it seems good. I tested it with Boss DD-3 and MXR 6-band EQ.
With Boss CE-1 it's not the best. Somehow it sucks more tone than with other amp.
I hope soon I can make test with Retro Sonic Chorus and Boss RV Pedals.

Many thanks to everyone that helped!

[EvS]

effects loop

There was some mention that some effects work better than others in the OTT effects loop mod. That is likely caused by the high output impedance of the 'send' output. That is being driven off of the plate through a 100K resistor, then the pot. In any case, unless the input impedance of the effects unit is really high, you will lose gain and it will likely affect the frequency response / tonality as well.

I've got an OTT and I have performed the Merc Magnetics tranny swap and mod and the amp is great but I too would like an effects loop in this amp. What it really needs is some kind of driver/receiver for the effects loop to eliminate any undesirable impedance mismatches.

If I come up with something useful I will post it.

Cheers

[Yasushi0802]

Hi all.

I now have to make a clone of an Tiny Terror.
Now I'm lost in the decision of the primary impedance of the output translator.
Advise people who do not?

Thanx.

(I am Japanese. Not very good with English.)

[Yasushi0802]

[Thomeeque]

Hi all.

I now have to make a clone of an Tiny Terror.
Now I'm lost in the decision of the primary impedance of the output translator.
Advise people who do not?

Thanx.

(I am Japanese. Not very good with English.)

Hi! I don't know any parameters of original Tiny Terror's output transformer, but here they sell OT for 2xEL84 amplifier and they declare load resistance Ra-a = 8000Ω (OT's primary impedance IMO should match this value, so it should be 8000Ω as well):




And OT I have used (from different source) has there Ra-a = 8kΩ as well, so I can sort-of approve it

Good luck (and sorry for such late answer)!

T.

[Yasushi0802]

Thanx!

Very well understood.
Thanks for your kind answer.

[sundevil98]

Can anyone re-host the TT15.jpg file please?

I can't download it because the link is dead.

I just picked up a "broken" TT for $150, and want to try to "fix" it, I figure if I have the correct schematic, it should make that job a bit easier. (Although, I'm fairly new to working on tube amps... I've only modified my Blackheart amps, but have been doing some reading, so I think I might be able to tackle this).

Anyway, this thread seems to have the most info on working with these amps that I can find, so I hope someone can help me out! If you have the file, but can't re-host, please e-mail it to me at blizakowski@gmail.com

Thanks!

[Thomeeque]

Can anyone re-host the TT15.jpg file please?

I can't download it because the link is dead.

TT15.jpg

OTT.pdf

I just picked up a "broken" TT for $150, and want to try to "fix" it, I figure if I have the correct schematic, it should make that job a bit easier. (Although, I'm fairly new to working on tube amps... I've only modified my Blackheart amps, but have been doing some reading, so I think I might be able to tackle this).

Hmm, "broken" TT for $150, lucky you! Good luck with the fix! Just be careful about those high voltages inside, you know..

Anyway, this thread seems to have the most info on working with these amps that I can find, so I hope someone can help me out!

Yes, definitely the best place in the world OTTwise!

Thanks!

You're welcome!

Cheers, T.

[gtrbryan]

Master Volume Values

Well, I'm FINALLY ready to begin my Tiny Terror build. Before I do, was there ever a consensus on the value of the master volume pot (100k v 500k)? I have seen schematics with both and purchased both. What have those of you who have built this amp used?

[Thomeeque]

.. What have those of you who have built this amp used?

470k

Good luck! T.

[dnpqkc]

More highs

I am looking at admiral's schematic for this. Does anyone know which caps or resistors to toy with to get a little more highs out of this thing? I am also experiencing the "honky" sound. Needs to be a little brighter.