New OT - less headroom and volume

[Redsparowe]

The stock OT died on me, had it replaced with the modulus (https://modulusamplification.com/18-wat ... 3101-p.asp). The USA options were just too expensive to import to the UK so no MM or heyboar etc.

Tech installed it for me. Amp came back and sounds fine but it's lost overall output and there's really no clean on the volume dial at all now.
Previously I'd be running it with volume on 2 and it would be a nice clean that was loud enough with the band. Now volume on 2 is full on crunch and I can't hear myself with the band.

I know people talk about how different OT sound different but I haven't been able to find a single post with anything actually objective other than stupid words like "sweeter" describing how transformers sound different. So, what should I actually expect from using a different OT? Is such a volume and headroom drop an expected change?

If the new OT isn't the issue, what else could be the fault?

EDIT: the amp is a marshall 1974x

[Bieworm]

To really know what’s going on will maybe be more clear when you take the voltages. I.E the screens, the plates and the cathodes of the EL84 tubes

[JMPGuitars]

What Bieworm said. But you should use the full voltage chart from the downloads section and get the B+ line voltages etc. If your distortion happens at low voltages, it may not be the power tubes creating the distortion. The B+ line voltage dropping too low could effect the whole amp. The tech could have also screwed something up, or the OT could be defective, or the PT not putting out enough voltage.

If you're new to this, read the safety precautions on the homepage.

[Redsparowe]

Thanks

It's currently back at the tech that installed the transformer, just to check things over and do some other minor bits. I'll get some measurements when it's back.

As a more general question; is output volume/headroom a thing that is affected by swapping OT?
ie, could I get more headroom/volume by choosing a different OT?

[Bieworm]

Of course it is. That’s why people prefer some types and brands over others…

[JMPGuitars]

You'll hear differences with similar specs, but then when you change the specs it obviously can become a lot more noticeable. Good 18W OTs tend to be way over spec'd. Though it's interesting because I use the MM 40W OT for some of my 36W builds, and it sounds great but isn't that big.

[Redsparowe]

Of course it is. That’s why people prefer some types and brands over others…

You make it sound obvious but I've never seen anyone say they prefer one OT to another because of volume. Usually people just use meaningless words like sweet or warm, I have seen people refer to compression before but never volume.

[Bieworm]

Of course it is. That’s why people prefer some types and brands over others…

You make it sound obvious but I've never seen anyone say they prefer one OT to another because of volume. Usually people just use meaningless words like sweet or warm, I have seen people refer to compression before but never volume.

Well, for example.. I know a guy who has a Super Reverb OT in this tweed Super. Much bigger OT! This amp is louder and ballsier with the same voltages as before with the tweed OT.
Also, when you take 2 20 watt OT’s with different primary impedances of 6k and 8k, the OT will compress earlier with the 8k one, thus have more volumes or headroom with the 6.6k