LC15R Output Transformer

fred
MortalMortal
Posts: 34
Joined: Tue Nov 10, 2009 8:38 am
Location: U.K.

LC15R Output Transformer

Postby fred » Sun Nov 20, 2011 8:30 pm

The general opinion is that the output transformers on these little amps is only just fit for purpose. Apparently they are too small / weak for the task in hand and failure is common. Seems it is true.

Several months back I plugged a THD Hotplate into my little LC15 turned the Gain and Volume up to maximum and ripped into Voodoo Child. I barely completed the opening riff before the amp squealed and then died, total loss of sound.

I put the amp in the garage thinking that it was well and truely goosed and would be far too expensive to repair. I contacted a couple of local amp techs for advice and they agreed it probably wasn't worth it.

Anyway, while having a garage clearout I came across the amp and was about to bin it when I remembered just how good it used to sound. So I decided I should really take a look at it. After all to replace it with a new little valve amp you would have to pay around £150, for a Cub for example.

So as the internet suggested the transformer was at fault that is where I would start.

Image

Pulled out the transformer and measured the resistances of the primary coils and output coils.

Image

Image

I didn't know if the values were good or bad but I went ahead and bought a replacement anyway.

A new transformer was £22.50. I measured the new transformer to compare, damn, the readings were almost identical. Oh well may as well put in the new one anyway.
The amp works ! ! ! Sounds as good as I remember. :D
I guess measuring the resistance of the coils is not a good way to test a transformer. :oops:

Anyway a great sounding little amp is back in action.

Image
Laney AOR PTL 50, Laney AOR PTL 50 (6L6), Laney LC15R, Mesa Express 5:25
Custom built stratocaster, Fender Custom Shop 57' Stratocaster, Burny LP RLG55

User avatarDavidDenson
ModeratorModerator
Posts: 238
Joined: Thu Nov 03, 2011 5:11 am

Re: LC15R Output Transformer

Postby DavidDenson » Mon Nov 21, 2011 5:13 pm

Great to hear that this little baby is back to producing sounds!

But I gotta ask....did you really need to use a hotplate with it? Was it really that loud?? Doesn't seem like it would be too loud as is..without an attenuator...not at 15 watts anyway.

Just curious, I don't have an LC15 and haven't heard one. I do have an LC30II, and it DOES get loud!
Amps:
Laney AOR 100 8 Knob
Laney LC30II
Fender Frontman 25R

Laney Cabs:
AOR 2x12 G12M70s
AOR 4X12 G12M70s
4x12 G12P80s

Guitars:
Epi LP Custom
Burny LP Custom
Charvel Model 1
Charvel Model 1C
Custom SuperStrat
Xaviere Acoustic/Electric
Alvarez Classical

fred
MortalMortal
Posts: 34
Joined: Tue Nov 10, 2009 8:38 am
Location: U.K.

Re: LC15R Output Transformer

Postby fred » Mon Nov 21, 2011 9:55 pm

The LC15 as you say is a 15 watt amp. They are amazingly loud. Really, really loud. Only reason I plugged the hotplate in was just to hear how the amp would sound with those EL84's running at full power. Unfortunately, as I said it lasted less than 10 seconds, so really I am none the wiser. I guess giving a 16 year old (1994) amp with a weak OT that sort of treatment was bound to end in tears.

I have in the past had a Blackheart BH5 (5watt) and that was amazingly loud at full volume. Also my Mesa Express 5:25 is also stupidly loud when on the 5watt setting.

I believe people do say that 50 watts is really only suitable for playing outdoors to a couple of thousand people. :wink:
Laney AOR PTL 50, Laney AOR PTL 50 (6L6), Laney LC15R, Mesa Express 5:25
Custom built stratocaster, Fender Custom Shop 57' Stratocaster, Burny LP RLG55

lionhead0043
HephaestusHephaestus
Posts: 70
Joined: Mon Oct 08, 2007 12:58 pm
Location: Greater Georgia (NOT Atlanta..)

Re: LC15R Output Transformer

Postby lionhead0043 » Sat Nov 26, 2011 1:47 am

Image
'83 Strat
LC15R or...
Lionheart L20H #0043 into M@&$€>#% mg412
Loopmaster 2 channel Effects Loop
Crybaby wah /Dano trem /Barber Burn Unit EQ od & Barb EQ eq
Digitech Timebender dd & Bass Synth wah
Just add riffage.!
FreewaterNOW

lionhead0043
HephaestusHephaestus
Posts: 70
Joined: Mon Oct 08, 2007 12:58 pm
Location: Greater Georgia (NOT Atlanta..)

Re: LC15R Output Transformer

Postby lionhead0043 » Sun Nov 27, 2011 1:40 am

That's a nice looking cab, Fred .
Um, i MEANT to say i've been real lucky with my LC15R; but i have also
babied it- it was( and still is) some of the best little LOUD i have ever
heard. i even bought it it's own 4x12( ok, it's a cheap ass marshall MG
series pawn shop find -$125 USD-that i needed anyway for the L20)!

i was hoping to upgrade it someday, and i had heard that a
better transformer was one way to go - good luck and keep us posted.
Peace
'83 Strat
LC15R or...
Lionheart L20H #0043 into M@&$€>#% mg412
Loopmaster 2 channel Effects Loop
Crybaby wah /Dano trem /Barber Burn Unit EQ od & Barb EQ eq
Digitech Timebender dd & Bass Synth wah
Just add riffage.!
FreewaterNOW


Return to LC (1995 - Present)

Who is online

Users browsing this forum: No registered users and 1 guest

cron