Ohmed and Confused

[Larry]

OHMS They are driving me crazy. I swear i have searched the entire interweb looking for something similar to this. Since I have decided to get the THD Hotplate I need to know which Ohm I am running (or should be ) I currently am running a Marshall TSL 60 with a 1960a Cab. Do I have this set right. Im curious to see if i should be using 16 ohms. Also where does 8 and 16 ohms differ at. Is one better than the other? And which Ohm Hotplate should i order?

A picture is worth a thosand words

 

[NorM]

The important thing here is they match. It looks like you can set everything to 16 Ohms. Do that. This is a great question that doesn't get covered much.
Less resistance = louder and more wattage to the speakers
More resistance = not as loud
unbalanced resistance = power being either dissapated as heat, not sound or power being reflected back to the source. The latter can cause permanent damage to power amps. A friend of mine has repetitive imperical data to this with a Marshall head(s).

 

[Larry]

Thanks NorM So I should order the 16 Ohm Hotplate correct?

 

[Larry]

I just got the Amp about four days ago. And have played it for less than 30 mins. I dont think anything has been hurt. I switched it to 16ohms on both. Thanks for saving me a headache.

And the cable is just a heavy gauge speaker cable that guitar center gave me when i bought the cab thanks again all

 

[Larry]

no way its too loud i keep it at like 1 -2

 

[tommyindelaware]

The important thing here is they match. It looks like you can set everything to 16 Ohms. Do that. This is a great question that doesn't get covered much.
Less resistance = louder and more wattage to the speakers
More resistance = not as loud
unbalanced resistance = power being either dissapated as heat, not sound or power being reflected back to the source. The latter can cause permanent damage to power amps. A friend of mine has repetitive imperical data to this with a Marshall head(s).

well ya don't say....
what are ya...some kinda rocket scientist or somethin ?????

 

[jeffrey]

You can mis-match ohms at low volume without much (if any) damage to anything. It's when it's done at higher volumes that it becomes a problem.

As previously stated, get your stuff swapped over to 16ohms mono and stay there. You should be fine.

 

[lenny]

NO, YOU DO NOT HAVE IT SET RIGHT!!!!

Right now you have an impedance mismatch...which is BAD!!! Your cabinet is selected for 4-ohm mono, and you're using the 8-ohm output on your amp. What you need to do, before you play another riff, is to move your speaker cable over to the 16-ohm jack on you cabinet!!! Then flip the "select" switch on the back of your amp to 16-ohm. Do not adjust the "mono-stereo" switch on your cab...LEAVE IT IN MONO!!! If you've been running your amp as you have pictured, then Marshalls' are tougher than advertised!

As for your THD Hotplate question, you need one that will work for 16-ohm mono. (Unless you want to buy another Marshall 4x12 cabinet.)

Hope that helps

Gary

PS-nice looking speaker cable...very sturdy. Brand?

+1

2 16 ohm Cabs =8ohms
2 8 ohm cabs =4 ohms
I have the Xact same Rig nice choice!!!

 

[jazzbo jim]

Larry, before you drop big bucks on a hot plate, you owe it to yourself to check out the Weber products. Give Ted Weber an email and explain your objectives to him and he will give you great, honest advice. Great customer service! (The EBMM of speakers )
Let me know what you decide to do.

 

[peat]

loving the fretboard on your axis lenny

 

[Larry]

how could i tell if i did any damage to amp/ cab im just paranoid

 

[blackspy]

I, so, want that Barretta.

 

[lenny]

I, so, want that Barretta.

SHes a true Rarity 1985 no luthier joint neck No serial number backplate was made for the NAMM show as a demo ,all the cavs are unpainted and all the dates are in the neck joint, neck and pickup route ,the boys at the Kramer forum want a crack at her as well but it stays here!
And its also at the shop getting sprayed Pink as we speak

 

[NorM]

how could i tell if i did any damage to amp/ cab im just paranoid

If it still works you should be OK. No go rock out with your bad self.

 

[Adwex]

Lemme chime in here. I'm not a rocket scientist, but I am an Engineer, but that's not what qualifies me to speak on this subject. A few years ago, I learned a very expensive lesson in impedance matching.

Don't mismatch impedance.

There's absolutely no advantage to mismatching, it doesn't get louder or softer, it just runs the risk of blowing your output transformer. How do I know this? I have a 2x12 (8 ohms) and a 4x12 (16 ohms or 4 ohms)...I switched to the 2x12 with the amp set for 16 ohms. After playing for a bit, the amp shut off. Replaced the fuse, turned it on, the fuse blew again. Guess why. The lower than "expected" impedance caused too much current to be drawn, and the output transformer windings over heated and eventually shorted out. Solid state amps are more forgiving, but tube amps like to be matched.

A costly lesson. Since it was a Marshall, the transformer had to be ordered from England. Yadda yadda yadda, after a month in the shop and a $300 repair bill, I'll never mismatch impedance again.

 

[nad]

Nice amp pron boys! Good choice on the TSL too.. I was going to plop for a TSL60 but I sat down with one and the power down switch on the TSL100 swung it for me. Plus over here in the UK - Marshall amps are so fantastically cheap.

The TSL100 I picked up is a bit special though - I'm having to get it transferred from another store and I should have it by this time next week - it's a limited edition Blue Vinyl, salt'n'pepper grill and small 6" gold logo version, the only good photo of the range I could find was of this DSL:

Absolutely stunning in real life (aside from the headstock!), I can't wait!

 

[SteveB]

+1

2 16 ohm Cabs =8ohms
2 8 ohm cabs =4 ohms

Correct assuming parallel wiring. But then, you never really see any series wiring with cabs these days, do you?

 

[beej]

Larry, before you drop big bucks on a hot plate, you owe it to yourself to check out the Weber products. Give Ted Weber an email and explain your objectives to him and he will give you great, honest advice. Great customer service! (The EBMM of speakers )
Let me know what you decide to do.

+1

Weber makes some fantastic products and Ted knows what he's doing.

(Anyone interested in speakers, he reconded my dead early 60's pre-Rola greenbacks with his own custom doping and they sound PHENOMENAL.)