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Laney Iron Heart IRT 120H head problem

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Re: Laney Iron Heart IRT 120H head problem

Postby ef37a » Thu Apr 11, 2019 10:36 am

Wonks wrote:
Howdy Doody Time wrote:The valves came in a pack of three, plus a single in a different package. So no hope of matching them. Nevertheless I am not hearing hum, so whether I was lucky, or Laney (since they don't mention matching) must have designed the circuitry somehow to account fora mismatch.

As I said in one of my posts, Laney do state in the manual that the power valves should be replaced as a matched quad set. It's not made that obvious (nothing in bold type or in any warning section), but it's there. Almost on the last page of the English section of the manual, rightbefore the signal flow diagram.

Just mentioning it for correctness.

Great news that it's working!

Yeah, Manufacturers put a lot of A saving stuff in manuals! Some will state that you MUST use exactly the right impedance speaker when there is no such thing and it is not THAT critical anyway. Some say use of a power soak will wear out the OP valves. True but no faster than playing 7 nights a week at full chat in a club.

Some warnings are I understand required by law? Electrical safety is paramount of course but I always smile about the SPL charts? The punter has bought a 50W combo with two V30s in it..What's he gonna do?

As far as valve matching goes, a very big unbalance will lead to hum and some reduction in clean power but where balance really matters it has to be much better implimented. Not only DC balalnce of the OP valves but LF and HF balance of the drive from the PI.

Dave.
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Re: Laney Iron Heart IRT 120H head problem

Postby Howdy Doody Time » Fri Apr 12, 2019 9:04 am

Mr. Wonks, indeed you are correct:

"Typical output tube problems can include a blown HT fuse, sound lacking in punch, sound lacking extreme highs or low, and low level hum. The output tubes can be replaced singly if you replace them with the exact same type AND grade as factory fitted, otherwise they should be replaced as a matched quad set in the IRT120H, or a matched dual set in the IRT60H"

Nevertheless, the 3 plus 1 thing didn't make a hap'orth of difference, thankfully.
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Re: Laney Iron Heart IRT 120H head problem

Postby Wonks » Fri Apr 12, 2019 9:13 am

They often get graded and a number or letter put on the packaging, so they will send out all no. 40s or letter Bs etc.
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Re: Laney Iron Heart IRT 120H head problem

Postby Howdy Doody Time » Sun Apr 14, 2019 7:47 am

Well after all that, I plain don't like the amp. It's not that I don't like it really, more like I bought the wrong one, on impulse, and it was fairly cheap, and handy, and big, and impressive looking.

So I bought another one. A Laney L20 Combo. New this time, didn't fancy another round of Valve swapping.

Well I must say I love the L20. Creamy British retro tone and retro looks. Wouldn't be out of place on a mid '60s stage.

Handy thing about the 120H and Cab is that the L20 sits very comfortably on top of it (ok maybe a little high for adjusting the knobs)

Lovely thing.
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Re: Laney Iron Heart IRT 120H head problem

Postby Howdy Doody Time » Mon Apr 22, 2019 12:01 pm

Aww shucks!

The new preamp valves came today so I thought I might as well change them. So now the 120 has all new valves, 4 preamp and 4 power.

And it sounds great.

What the hell, having 2 valve amps never hurt anyone.

My problem is I have no patience.
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