Ibanez TSA30 Mains transformer

[Vitrolin]

A friend has Ibanez TSA30, he was playing loud for a long time then it died..

He measured the primary side and seems as the internal thermal fuse has blown, so he asked me if i knew what the mains transformer for his Ibanez TSA30 was.
i tried google and only found this schematic http://gravinatubeamps.com/2014/08/02/ibanez-tsa-30-u-schematic/ that lack exactly what i am looking for.
so does anyone have a full schematic, have TSA30 you can open to take some measurements, or by some other reason know what the transformers secondary voltages are, the would bring a lot of joy.

[Vitrolin]

last night after posting i got a great idea and i wrote ibanez they replyed first thing in the morning with a schematic

so sometimes its so easy to get an answer, just direct your question to the right place

[J M Fahey]

Cool, now post it here    for technical suggestions.

[Vitrolin]

i was convinced that i did, but something didn't go well

[Vitrolin]

by the way i guess that the voltages are noted after rectification
400*1,4=560Vdc wouldn't it be to high for only 30W?

and the bias is only half-wave rectified
47*0,7=33vdc

[J M Fahey]

Weird but I definitely have seen this on Roland/Ibanez amps, maybe it's a Japanese thing.
As in "44+44V" (obviously DC)  rails being fed from "44+44 V" transformers , in the parts list or other schematic versions they were identified as "35V " transformers, end consensus was that in **some** amps Japanese refer to transformers (which they probably don't even design but buy from giant OEM suppliers) by "the voltage (DC of course) you will get by using that transformer"
I found no other explanation.
If design work is very compartamentalized, split in many areas not communicating at low level, amp designer *might* spec: "my amp needs 42+42V rails at 2.5A DC , please source 1000 transformers for them within 30 days"
Not as weird as it seems for us Electroguys, a car designer might order  "an axle of such and such dimensions, such tensile strength, such Brinnell surface hardness, such polishing and tolerance" and neither specify nor care about steel composition, tempering, annealing, etc. , just that it meets or exceeds his goals.

So I read this transformer as:

* P14-P15: 400*.707=283VAC (290V?) winding @ as many mA needed for this 30W amp.
I bet 200-250mA would be acceptable, anything above a bonus.

* P16-P17 47*.707=34VAC . 35-36VAC would be fine too.
Any current rating is fine, almost 0 consumption there.

* P18-P19 and P19-P20 those are never converted to DC so "they are always 3.15+3.15VAC" .  Not very consistent, huh?

* P21-P22 ... now the plot thickens ... considerably.
This "13VAC" winding is rectified through a bridge and is regulated by a "7810".

So in theory we have 10VDC there and everybody is happy.

*Problem* : those 10V DC power *both* V1 and V2 filaments, each in series so needing 12.6V DC *and* the TS circuit requiring nominal 9V ... so 10V DC is wrong on both counts.
Maybe the designer had a brainfart and thought that "splitting the difference" was a good idea?
Not to me.

I would wind P21-P22 to, say, 13VAC as shown , get some raw 17/18VDC (would also increase C20 to 1000uF or even 2200uF if it fits) , use a 7812 regulator for true 12VDC filament voltage (well within spec) and increase value of R46 from original 110r (what's used in the TS pedal version) to 1k or 1k2, which should drop voltage to about 9V DC .

This winding should be specified for some 400-500mA.

[Vitrolin]

yes that is very much what i was thinking, the given voltages are what is finally needed, execept that 13V, used for 10V.
i havent seen the the amp myself, maybe it isn't connected as shown in the schematic, maybe the heaters are connectet to the un regulated dc, not after 7810, bu why aren't they supplied with the power tube and phase inverter heaters??
my friend called me for help, figuring out the transformer, he says he wants to fixit himself, hes a trained technician so he will be ok i think.

[Gustaf]

Hi,

I just joined the forum.
Just found this thread searching for information on the TSA30 Amp.
I need to convert an imported 110V TSA30H to 230V operation.

Does anyone here know where i could get a "TSA30-PT/23050" transformer. I asked the Swedish supplier but they said they couldn't get it for me, referring to the fact that the amp is no longer in production. Still, I see several models including the TSA30 Combo still on the Ibanez website...

Any advice and suggestions are welcome!

Best regards,
Gustaf
Sweden

[phatt]

Yes a transformer swap would be ideal but judging by this posting that may not be easy to find. 
You may find a step down transformer will likely be easier to find.
Phil.

[J M Fahey]

Agree.
Japanese in general keep replacement parts for 3 years to back up models they sold but after that it's anybody's guess, I have been told by by Yamaha Argentina and Yamaha Japan that I had to junk an expensive Classic nylon strings guitar (bad preamp problems)  because it was "old" (4 or 5 years)  and "obsolete" , "please buy another one" .

And your transformer *is*  complex, 9 secondary wires in total, not what can be easily replaced by, say, a generic Fender tube amp aftermarket one.

Guess your carry bag will include a 230/115V stepdown transformer , it's the practical solution.

[Vitrolin]

hey gustaf
i was informed by the swedish supplier that they didnt have any could but the factory had some they could order for me.
the amps owner didn't have interrest in buying the transformer at the moment so i dont know what what the final price is. also i think theyre very strict about not selling directly to consumers.

[Gustaf]

Hi,

I big breakthrough!

First of all, thank's for all replies! Really grateful the support :-)

So, I contacted Headstock Distribution today, they asked me to send them an email with the part number and S/N of my amplifier. And could sell me a transformer delivered to me in Sweden for $65. Super nice on the phone too!

So that's the solution to my problem for this time!
And... it also means I have a fully functional spare 120V / 60Hz TSA30 mains transformer ;-)

Headstock DistributionLtd.
Unit G1 Coombswood West, Steelpark Road,
Halesowen, B62 8HD, UK
Tel.+44 (0)121 5086666

/Gustaf

[J M Fahey]

Cool !!! 

I call that lucky 

[Mprall00]

Know this is old but just wanted to follow up here to say i did change to 7812 regulator.  Lowered the noise floor of the preamp and sounds a lot better.  But when i put in the 1k resistor for r46 it dropped the voltage to 5v.  220r put it right at 10v.  Sounds fine.  In case anyone else stumbles on this like I did I wanted to share.

I have changed a ton in this amp now.  When i am 'done' i'll do a different post to try to cover everything.

What I am trying to do now - NFB loop so I can add a presence control.  Keep getting screeching positive feedback even when i flipped the OT primary...  Might give up on that one.