Anyone know what the "tiny terror" circuit is?

[gtrbryan]

One more Tiny Terror Question OT primary

I've seen real OTT today (bought by my friend yesterday), label on PT states 250VAC secondary with 185VAC tap (unfortunately nothing about current). Thmq

Many Thanks. My PT (A weber WPTGP)
https://taweber.powweb.com/store/PTGPsch.jpg can give me 250 or 210 secondary. I will be a little high on the 7 watt but I guess I can kick it down with a resistor before B+ if necessary.

My next (and hopefully last) question involves the OT. I'm using a Hammond 125E. This is a "universal" for push pull circuits. I would like to wire two outputs, one for 16 ohms and one for 8 ohms.

My question is what primary impedance on the OT should I use for the amp? The el84 data sheet says 8,000. http://tdsl.duncanamps.com/show.php?des=EL84 Should I go a little lower as I've seen done before (6,600??)? Would that would be better with the lower voltage option?

Also, there is no 16 ohm secondary option on the 125E hookup data. I assume I could just extrapolate out to 16 ohms using my high school algebra? If so, My choices are 5,983 or 8,533. Any thoughts?

http://www.hammondmfg.com/125.htm

If you could take one more look at your friend's amp to see the OT impediance it would be greatly appreciated!

[Thomeeque]

Many Thanks. My PT (A weber WPTGP)
https://taweber.powweb.com/store/PTGPsch.jpg can give me 250 or 210 secondary. I will be a little high on the 7 watt but I guess I can kick it down with a resistor before B+ if necessary.

My next (and hopefully last) question involves the OT. I'm using a Hammond 125E. This is a "universal" for push pull circuits. I would like to wire two outputs, one for 16 ohms and one for 8 ohms.

My question is what primary impedance on the OT should I use for the amp? The el84 data sheet says 8,000. http://tdsl.duncanamps.com/show.php?des=EL84 Should I go a little lower as I've seen done before (6,600??)? Would that would be better with the lower voltage option?

Also, there is no 16 ohm secondary option on the 125E hookup data. I assume I could just extrapolate out to 16 ohms using my high school algebra? If so, My choices are 5,983 or 8,533. Any thoughts?

http://www.hammondmfg.com/125.htm

I'd say you should go with those 8.2/8.5k, but my knowledge here is very weak, hopefully somebody else will be able to tell more..

If you could take one more look at your friend's amp to see the OT impediance it would be greatly appreciated!

OT on friend's amp has just very simple label mapping taps with colors of wires and that's it - no other specs

T.

[gtrbryan]

Tiny Terror Layout

I have been working on my Tiny Terror Project this weekend. I thought I would post my layout should anyone wish to use it. I did not include the power supply. Also, any comments / corrections are welcome.

[Steve A.]

I have been working on my Tiny Terror Project this weekend. I thought I would post my layout should anyone wish to use it. I did not include the power supply. Also, any comments / corrections are welcome.

Thanks for posting your layout drawing! As for the OT, I've heard good things about Musical Power Supplies on the 18watt.com/ppwatt.com forum:

http://www.musicalpowersupplies.com/

Their story sounds a lot like OEI in the early days- a hobbyist who wanted better transformers for his projects so he came up with some designs that are being manufactured out of the country. Hammond transformers are more along the lines of "meat and potatos"... very dependable but maybe not the best choice for a killer boutique amp.

I haven't tried Matt's transformers yet but I will soon! Their OT15PP with 4, 8 and 16 outputs with 8000/7000 inputs sounds ideal for this project- $24.95 plus shipping. Order more to save on shipping and to receive a small qty discount...

Steve Ahola

[calis]

Hey guys.

I posted in here a while back about trying to get a more AC15/AC30-like sound out of the Tiny Terror considering it is based off of the AC15. Just wanted to give a report on that. If you remember, my complaints were that, while I liked the sound of the overdrive, the amp was a bit too gainy and compressed sounding for my tastes. In the end, I just ended up changing V1 to a 12AU7 and that dramatically opened up the amplifier. I can still get just as much gain as I needed (with my SG plugged in I would turn the gain up to about 1 o'clock and now I turn it up to about 3 o'clock) before but it is now a clearer, more open, very responsive sounding distortion. This is exactly what I was hoping I could get out of the Tiny Terror. Anyway. Thanks to the Admiral for the advice. And I hope this helps some of you who may also be looking to change your Tiny Terror's a bit.

Justin

[sjwebb90]

Anyone with a Tiny Terror bought between October 2007 and August 2008 would be advised to read the following:

Important European Union

Safety Warning

Orange Amplification

Tiny Terror Head

We have become aware that some Tiny Terror Heads sold between October 2007 and August 2008 have a manufacturing defect.

The defect is in the mains transformer which may be unsafe.

If you own a Tiny Terror head please check the serial number on the rear of the amplifier.

The affected models are clearly marked ‘Made in PRC’ and have serial numbers as follows;


L070910001 to L070910989

L071110101 to L071110854

L080210001 to L080210986

L080410001 to L080410406

L080810001 to L080810964



Please note the following points;

- Only units sold in the European Unit are affected by this issue.

- Units sold in the USA are not affected.

- Tiny Terror combos are not affected only Tiny Terror heads.

- Korean build units are not affected.



If you have an affected amplifier please stop using it immediately. In the UK please contact us at workshop@omec.com or on 0208 905 2828 ext. 211, outside of the UK please check our website for details of the distributor in your country and contact accordingly. Your amplifier will then be arranged for collection then modified.

If your amplifier does not meet any of the above criteria it is not affected by this issue and is perfectly safe to continue using.

If you have any queries please do not hesitate to contact Orange Music on +44 (0) 0208 905 2828.

We wish to thank you for your co-operation and apologise for any inconvenience.

Orange Music Electronic Company Ltd, OMEC House, 108 Ripon Way, Borehamwood,

Hertfordshire, UK, WD6 2JA

[viktormoto]

Tinny Terror

I build self Tinny Terror amp 15 W. Working, bud have oscilation when put pot sensitivity-distorsion to half and more to maximum. The oscilation change frequency when moving with pot. I tried change capacitor 100Pf and 470 Pf, no effect
Can me enybody help
Thanks

[mathia]

Hi - basically, I had the same problem on the two clones I've built, with an annoying, frustrating noise sounding like feedback, even with the guitar off, with changing pitch, making the amp virtually useless. After much checking and poking, I ended up soldering the input 68K resistor as close to pin2/V1 as I could, and that seemed to fix the problem - I now have a flawless OTT clone, which is by the way very good sounding, don't ask me why... I never found the original OTT that pleasing, the sound being easily quite compressed.

[Thomeeque]

Ahoj, Viktore!

I had oscillations problem with my clone too, but in my case it was electro-magnetic feedback between output transformer and input circuitry - I did solve the problem by adding metal shield there - check photos here (DSCN6677_preamp_guts_detail.jpg -> DSCN7343_ot_shield_installed.jpg).

Good luck!

T.

[frank]

Whoa!!! that looks awesome! Nice work.

[Thomeeque]

Whoa!!! that looks awesome! Nice work.

Thanks, Frank!

[viktormoto]

Hi - basically, I had the same problem on the two clones I've built, with an annoying, frustrating noise sounding like feedback, even with the guitar off, with changing pitch, making the amp virtually useless. After much checking and poking, I ended up soldering the input 68K resistor as close to pin2/V1 as I could, and that seemed to fix the problem - I now have a flawless OTT clone, which is by the way very good sounding, don't ask me why... I never found the original OTT that pleasing, the sound being easily quite compressed.

Thank Mathia, I try it, the resistor 68k is near to pin 2 V1, it is better, bud the problem is not fixed.

[viktormoto]

Hi - basically, I had the same problem on the two clones I've built, with an annoying, frustrating noise sounding like feedback, even with the guitar off, with changing pitch, making the amp virtually useless. After much checking and poking, I ended up soldering the input 68K resistor as close to pin2/V1 as I could, and that seemed to fix the problem - I now have a flawless OTT clone, which is by the way very good sounding, don't ask me why... I never found the original OTT that pleasing, the sound being easily quite compressed.

Ahoj, Viktore!

I had oscillations problem with my clone too, but in my case it was electro-magnetic feedback between output transformer and input circuitry - I did solve the problem by adding metal shield there - check photos here (DSCN6677_preamp_guts_detail.jpg -> DSCN7343_ot_shield_installed.jpg).

Good luck!

T.

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:
http://viktormoto.rajce.idnes.cz/GUITAR_AMP/#album

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

[benjy]

FX Loop

Hello,
I'm new in this forum and I found very useful information here.
I'm building a FX Loop to my Tiny terror but I have one problem. My technical knowledge and English are not enough to understand one explanation I found:

A circuit trace is broken just after the wiper of the second of the dual-gang volume controls, and some copper cleaned for soldering either side. Physically it's the back wiper of the two; from there the trace goes to the PI. Two little holes are drilled into the cleaned copper either side of the break; these are for the signal wires to and from the send/return jacks. They are wired with screened cable - a third hole is drilled for both the screens into the earth trace used by the volume controls.

The send/return jacks are wired together in the normal way so the loop makes when the jacks are out and breaks when they're in.

It's not hard to do if you choose the place to cut the trace where there's a bit of room around the copper, and drill very carefully. The trace is quite hard to cut as there's thick resin on top of it; it's a good quality circuit board. The holes have to be small, and the signal wires thin. The wires are kept short and have to be reasonably good quality or there might be some loss.

NB the loop is pre-MV - which is post-PI on this amp. But it does come after all of the the preamp's tone-shaping and gain circuitry.

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

and the schematic is here:
http://russosmusic.20m.com/TT15.jpg

This schematic seems right.
So my questions is where exactly I have to break the circuit trace? According the explanation above it seems to me that is after MV not pre. Is it true?
And what does it mean: "The send/return jacks are wired together in the normal way so the loop makes when the jacks are out and breaks when they're in." ?
What means "normal way"?
Thanks!

[Thomeeque]

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.