Hello everyone.
I have a problem with my SYN-2. The primary winding of the power transformer has burned out. Does anyone happen to have the specifications for this transformer (secondary winding voltages and currents)?
I’ve contacted the manufacturer, Synergy, about this but haven't received a reply yet.
I would be happy to buy a replacement transformer designed for European voltage (230V).
Synergy SYN-2 main transformer problem.
Moderators: pompeiisneaks, Colossal
Synergy SYN-2 main transformer problem.
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Stevem
- Posts: 5604
- Joined: Fri Jan 24, 2014 3:01 pm
- Location: 1/3rd the way out one of the arms of the Milkyway.
Re: Synergy SYN-2 main transformer problem.
So it does not have voltage spec’s on a tag on its perimeter?
Isn’t that a tag on its side I kinda see?
So it went open yet did not blow the fuse from an overload condition before that winding went open?
Isn’t that a tag on its side I kinda see?
So it went open yet did not blow the fuse from an overload condition before that winding went open?
When I die, I want to go like my Grandfather did, peacefully in his sleep.
Not screaming like the passengers in his car!
Cutting out a man's tongue does not mean he’s a liar, but it does show that you fear the truth he might speak about you!
Not screaming like the passengers in his car!
Cutting out a man's tongue does not mean he’s a liar, but it does show that you fear the truth he might speak about you!
Re: Synergy SYN-2 main transformer problem.
All internal fuses in the SYN-2 are fine, and there are no signs of any damage. Measurements of the power supply inputs show no short circuits on the secondary winding side. However, the primary winding reads 0 ohms (it is shorted). There is no descriptive label on the transformer. It’s a stressful situation. I don't even know how the transformer got damaged; the SYN-2 was used a few days ago and everything was fine. Yesterday, when I tried to record something, the SYN-2 wouldn't start up, and the fuse in the power socket had blown.
Re: Synergy SYN-2 main transformer problem.
Transformers do sometimes just die. However, it is quite unusual. That's why it is a good idea to conduct some more tests. Here are my thoughts based on your comments above.igorpog wrote: ↑Tue Sep 22, 2026 12:09 pm All internal fuses in the SYN-2 are fine, and there are no signs of any damage. Measurements of the power supply inputs show no short circuits on the secondary winding side. However, the primary winding reads 0 ohms (it is shorted). There is no descriptive label on the transformer. It’s a stressful situation. I don't even know how the transformer got damaged; the SYN-2 was used a few days ago and everything was fine. Yesterday, when I tried to record something, the SYN-2 wouldn't start up, and the fuse in the power socket had blown.
Yesterday, when I tried to record something, the SYN-2 wouldn't start up, and the fuse in the power socket had blown.
I would remove the transformer from the chassis, as you already have done, then re-try plugging it in and turning it on. It is possible that something before the primary is defective. If it is, the socket fuse will blow again. This is based on no fuses inside the unit blowing, only the AC socket fuse.
the primary winding reads 0 ohms (it is shorted
The wire resistance on transformer windings is quite low, especially on a toroid. It can take special meter connections to measure it accurately. Your meter may have shown 0 ohms, but the transformer still be OK, because of the measurement difficulty. Or, it may be dead. I suggest some additional tests.
1. Test your meter. Measure the resistances of another transformer if you can, or a quite-long wire to see whether it can tell you the difference between a true short (meter leads touching) and a merely low resistance, down under 10 ohms.
2. Remove the transformer from the chassis (as you already have) and spread its leads out so no lead-wire touches any other lead.
3. Label the leads somehow so you don't mix them up, then measure between each lead and every other lead. Write the measurements down - a table is nice and helps in referring later. This tells you exactly what is connected to what, and whether any winding is shorted to another winding. It also tells you whether any winding is open. It also lets you make quick comparisons. The primary is a high voltage winding, but the high voltage secondary is more so, and should be a higher resistance.
4. Do a pulse-inductance test. This tells you whether any winding is actually shorted. To do this, get a small neon bulb, like that NE-2. Hook this across the primary or high voltage winding. Momentarily connect a lower-voltage winding across a 6V flashlight battery, then remove it. If there is no shorted turn in any winding, the NE-2 will flash. If there is a short on any winding, the bulb will not flash.
5. If the pulse-inductance test is OK, use a different transformer to feed a low voltage, maybe 6.3V, into a winding. This lets you measure every winding's voltage to see if they are in the correct proportions.
This process will catch any power-line transformer fault, and often allow you to identify an unknown transformer.
"For every complex problem there is an answer that is clear, simple, and wrong"
H. L. Mencken
H. L. Mencken
Re: Synergy SYN-2 main transformer problem.
I am absolutely certain the transformer is damaged. It blows fuses even with the secondary windings disconnected. I have been servicing tube amplifiers for many years. My website is https://lampiakiserwisleszno.pl, and you can find me on Facebook at #lampiakiserwisleszno 
EDIT:
I have a company in Poland that manufactures very good custom transformers, but of course, I have to provide the exact voltage and current values.
EDIT:
I have a company in Poland that manufactures very good custom transformers, but of course, I have to provide the exact voltage and current values.
Re: Synergy SYN-2 main transformer problem.
No disrespect intended. Yes, if it blows fuses with just the primary connected, there is a internal problem.
Telling us that would have prevented me going off like that. We get many, many people who say things like "my amp quit working - it's a dead transformer, isn't it?" with no particular reason for thinking that.
Telling us that would have prevented me going off like that. We get many, many people who say things like "my amp quit working - it's a dead transformer, isn't it?" with no particular reason for thinking that.
"For every complex problem there is an answer that is clear, simple, and wrong"
H. L. Mencken
H. L. Mencken
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Stevem
- Posts: 5604
- Joined: Fri Jan 24, 2014 3:01 pm
- Location: 1/3rd the way out one of the arms of the Milkyway.
Re: Synergy SYN-2 main transformer problem.
Did you get a reply from the manufacturer yet?
If not then please tell us what this amp has for a tube complement and if the amp has any solid state circuits in it, and what output wattage it is stated as having.
If not then please tell us what this amp has for a tube complement and if the amp has any solid state circuits in it, and what output wattage it is stated as having.
When I die, I want to go like my Grandfather did, peacefully in his sleep.
Not screaming like the passengers in his car!
Cutting out a man's tongue does not mean he’s a liar, but it does show that you fear the truth he might speak about you!
Not screaming like the passengers in his car!
Cutting out a man's tongue does not mean he’s a liar, but it does show that you fear the truth he might speak about you!
Re: Synergy SYN-2 main transformer problem.
I bought a new, genuine transformer from Synergy. As you can see, their customer support is excellent. Thanks to Synergy.
I also measured the voltages and currents, and they turned out to be essentially identical to the parameters I had predicted.
The power transformer has a rating of approximately 40W.
The SYN-2 uses five 12AX7 tubes, resulting in a heater current draw of 5 × 0.150A at 12V. This totals 0.75A at 12V. The voltage at the module connector pins is 18V, meaning each module must have its own 12V heater voltage regulator. Consequently, the transformer output should be around 18V AC; after rectification, this yields approximately 25V (unloaded measurement), and after passing through the main heater voltage regulator (located on the SYN-2 PCB), it results in a final 18V supply delivered to the module connector. In summary, accounting for the higher current draw of cold tube heaters at startup, the transformer should supply about 1A; thus, the heater winding (the two blue wires) should be rated for 18V/1A.
The SYN-2 circuit employs 10 triodes (five 12AX7 tubes) with an anode current of approximately 1–2mA each. This results in a total current draw of 20mA at 300V. The anode voltage in the SYN-2 is stabilized and regulated (using a SAG circuit); therefore, the anode voltage winding should be rated for 300V/0.03A (with some headroom).
The supply voltage for the integrated circuits is the standard ±15V. Judging by the number of ICs, the total supply current should not exceed 0.3A. The transformer winding powering the ICs should provide 16–18V at 0.3–0.4A to ensure proper operation of the positive and negative voltage regulators.
Ultimately, the power transformer specifications should be as follows:
1) Heater winding: 18V/1A (blue-blue cable)
2) Anode voltage winding: 300V/0.03A (yellow-yellow cable)
3) IC supply winding: 2 x 16V/0.3A (reb-black-red cable)
The total winding power is 39.8W.
I also measured the voltages and currents, and they turned out to be essentially identical to the parameters I had predicted.
The power transformer has a rating of approximately 40W.
The SYN-2 uses five 12AX7 tubes, resulting in a heater current draw of 5 × 0.150A at 12V. This totals 0.75A at 12V. The voltage at the module connector pins is 18V, meaning each module must have its own 12V heater voltage regulator. Consequently, the transformer output should be around 18V AC; after rectification, this yields approximately 25V (unloaded measurement), and after passing through the main heater voltage regulator (located on the SYN-2 PCB), it results in a final 18V supply delivered to the module connector. In summary, accounting for the higher current draw of cold tube heaters at startup, the transformer should supply about 1A; thus, the heater winding (the two blue wires) should be rated for 18V/1A.
The SYN-2 circuit employs 10 triodes (five 12AX7 tubes) with an anode current of approximately 1–2mA each. This results in a total current draw of 20mA at 300V. The anode voltage in the SYN-2 is stabilized and regulated (using a SAG circuit); therefore, the anode voltage winding should be rated for 300V/0.03A (with some headroom).
The supply voltage for the integrated circuits is the standard ±15V. Judging by the number of ICs, the total supply current should not exceed 0.3A. The transformer winding powering the ICs should provide 16–18V at 0.3–0.4A to ensure proper operation of the positive and negative voltage regulators.
Ultimately, the power transformer specifications should be as follows:
1) Heater winding: 18V/1A (blue-blue cable)
2) Anode voltage winding: 300V/0.03A (yellow-yellow cable)
3) IC supply winding: 2 x 16V/0.3A (reb-black-red cable)
The total winding power is 39.8W.