Orange Tiny Terror Output Transformer Upgrade

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Strawtles

Well-known member
Joined
Mar 20, 2009
Messages
191
Hello, I am upgrading my Orange Tiny Terror guitar tube amplifier.
I have replaced  all the stock tubes, resistors and capacitors and now I want to replace the output transformer.
someone suggested to me to replace it with a Hammond 1750Y
It seems that this transformer is a great replacement  but it has the primary impedance of 6k2 Ohm while in the original one is 8K Ohm
Do you think this different impedance can affect the sound?
Thank you in advance
 
what is wrong with the stock OPT?  blown or you just want different tone?  better dependability?

have you checked out the Orange mod kit by Mercury?

http://www.mercurymagnetics.com/pages/mainframe.htm#catalog/kits/TinyTerror/Orange-TT.htm

yeah, kind of pricey  for an 18 watt amp and it sounds like you want to score a more reasonable priced OPT as you have already shelled out for tubes and such,  maybe borrow the choke idea,

that looks like a pair of EL84's with a dual master volume which always has been a favorite,

cool dual gain pot also,  that is a standard phase inverter drawn in a weird (reads different) way, a few values tweaked but pretty basic.

those tubes want about 7.5K to 8K but 6.5K would work fine.  replace the 470 ohm screen resistors with 1 K 2 watt to compensate for the increased load from the 6.5K  ac resistance (impedance)

you might try the Hammond 8K  output, Antique Electronic p/n P-T1750E.  $36.28
https://www.tubesandmore.com/products/transformer-hammond-output-replacement-fender-15w-8k

we can wind you a vintage Fender 8K as used in the 1959 Tweed DeLuxe but that is $50 and has a compressed sound without the brittle hi end, but the hi end on the 6BQ5 is awesome, so you might want something which will bring that out,

we like a 100 EI core with four sections of 645 turns = 2580T primary into  a three section 119 turn  secondary which sports a center section of 63 turns wound bi-fi for a 7.5K to 16 ohm job as used in the Fisher amps of yesteryear,

it is hard to tell what the 6.5K transformer will sound like just from the Z number. Best way to find out is to try it or search online blogs on Tiny Terror mods, which is probably where you got the idea,. Lower Z would predict less bass due to less inductance, hi end is a crap shoot as it will be determined by the coil, number of turns and wire size, interleaving, size of the core, etc.

have you heard the VOX Night train?    that is the favorite glove box amp over here,

http://www.prowessamplifiers.com/schematics/Vox/Night_Train_Updated.html

tiny terror>



 
Stock Tiny Terror amplifier sounds really good, but after to have compared it with a "Hard Wired" version ... nothing is the same. The difference is like day and night! ("Hard Wired" version is the same amplifier built p2p and with better components)
As the schematic is simple I have rebuilt my amplifier p2p with the same components used in the "Hard Wired" version (with the help of some pictures I found on the net)
Now the amplifier sounds better, but not as the  "Hard Wired" one from which it differs for the output transformer.
I have read about Mercury Magnetics transformers, but someone says they not worth the price they cost (they are a lot expensive)
Someone compared a Mercury Magnetics transformer with a Hammond 1750Y  in a Vox AC15 and the Hammond resulted better
I know this is subjective, but considering that the circuit of Tiny Terror is similar to the Vox AC15 one, and that the price for the Hammond transformer is less than half of the Mercury Magnetics one, I am considering to buy it ... but before I'd like to understand  what does the different input impedance.
Hammond 1750E is cheaper than 1750Y but I have read tht it is not the best choice for class A (or smilar amplifier)
 
dropping the Z down to 6.5K  is kind of like driving a semi up a hill and shifting from 3rd to 4th gear.

your engine will have to work harder to get up the hill and you will need a ring and valve job at 250K miles instead of 300K.

rpm's drop (voltage) but torque on the crank shaft increases (current)

power is about the same but tubes wear quicker.

frequency response is a full chapter from RDH4 as far as M, impedance mismatch and it's effects on your elliptical loadline




 
I think it's better to keep the stock transformer waiting until I will find a better one with the right input impedance  :)
 
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