ibanez tsa15h mods

[nosaj]

I got someone asking if we can get more output on this amp. It's a 15w amp. Looking at the PT I'm not so sure I can find another with similar taps an higher voltage. The ot probably the easiest .

My general inclination is to say Lets check it out first and see what it is putting out first as there may be an issue with it. Then from there I think if you want a louder amp buy a louder amp.
Some hoffman threads talk about pushing it up to 22w but not reall clear on how they're doing that.

Thanks,
nosaj
schematic included

[The Dude]

I don't see an easy way to raise B+. There's already no NFB (unless I missed it). You'd have to raise power output substantially for it to be noticeable. I think you're on the right track with "Lets check it out first and see what it is putting out first as there may be an issue with it. Then from there I think if you want a louder amp buy a louder amp". The only other thing I can think of would be to try a more efficient speaker.

[J M Fahey]

Short answer: no.
Agree with more efficient speaker.
V30 not only louder but nastier which increases the effect. Or Jensen C12N if American sound preferred. Again, bright aggressive sound makes it cut through better.

[nosaj]

Short answer: no.
Agree with more efficient speaker.
V30 not only louder but nastier which increases the effect. Or Jensen C12N if American sound preferred. Again, bright aggressive sound makes it cut through better.

just a question here, the v30 i found is a 60watt the g12 greenback is a 25watt i think. Being a 15watt head which would be a better choice or are they identical minus the wattage rating?

Thanks for chiming in Juan.

nosaj

[The Dude]

Look at the efficiency/sensitivity rating, which is the important thing here. Most of the time, lower wattage = higher sensitivity, but not always.

[nosaj]

ok so 98db vs 100db not much or am I wrong.

Also see a celestion A type series that might be promising.

nosaj

[Helmholtz]

ok so 98db vs 100db not much or am I wrong.

Well 2dB more corresponds to 60% more amp power, so 24W in your case.

[nosaj]

Well 2dB more corresponds to 60% more amp power, so 24W in your case.

ok so a 100db with a 15watt amp an 98db with a 15 watt amp there WILL be a noticeable difference in perceived volume, correct?
nosaj

[nosaj]

I found this neat database anyone else seen it?

[Helmholtz]

ok so a 100db with a 15watt amp an 98db with a 15 watt amp there WILL be a noticeable difference in perceived volume, correct?

Difference should be same as between 15W and 24W at the same speaker. Noticeable for sure.

[Mick Bailey]

Take a look here. I've used the Governor and Swamp Thang in 1x12 combos. The difference in volume compared with a run-of-the-mill 97db speaker is remarkable. Plus they sound good.

https://guitarriego.com/en-us/guitar...h-more-volume/

[nosaj]

Very informative article, i forwarded it on to the music store i work with.

Thanks,
nosaj

[vintagekiki]

My general inclination is to say Lets check it out first and see what it is putting out first as there may be an issue with it. Then from there I think if you want a louder amp buy a louder amp.
Some hoffman threads talk about pushing it up to 22w but not reall clear on how they're doing that. ¹⁾

¹⁾ Old school

In principle power of each amplifier can be increased by changing the OT and PT to desired power.
Eg. The difference between the Fender SF50 or 70 and SF100 or 135 is mainly in the power OT and PT.

When choosing PT, Ua and Ia should be defined for desired power. If use higher power PT (larger core, thicker wire) with same Ua and Ia, output tubes burns regularly, because depending on the (higher) excitation, OT pull a higher Ia and exceed dissipation threshold.

The power of the output stage depends from pover tubes voltage +Ua and the primary impedance Raa
The formula is simple
P = +Ua² / Raa

If we apply the formula to tsa15h we will get the data for the power given by the factory
P = 330² / 6000 = 18.15W
In order to get more power from tsa15h, need to raise +Ua to 370V with the same Raa
P = 370² / 6000 = 22.81W

We see difference between 18W and 22W only on measuring instruments.
The human ear notices a difference if is power of the sound source twice more.

Hamlet's (psychological) question is "18W or 22W"

to be continued ¹⁾

[J M Fahey]

V30 is noticeably louder than greenback and both usually louder than what ever is generally factory fit .
That said, that's an "above average" amp so they might have fitted a better than usual speaker.

[vintagekiki]

ok so 98db vs 100db not much or am I wrong.

Also see a celestion A type series that might be promising.

nosaj

There is a difference between electrical and acoustic power. Be careful not to replace terms.

The human ear can readily distinguish 3db changes in volume.... Less than 3db it's really difficult to definitively tell a difference.

https://www.everythingsg.com/threads/difference-between-98-db-and-100-db.28269/

1)
When replacing an existing speaker with a higher efficiency speaker (dBm), make sure the speakers are approximately the same in power.