You are here

Laney Iron Heart IRT 120H head problem

For all things relating to guitars, basses, amps, pedals & accessories.

Re: Laney Iron Heart IRT 120H head problem

Postby Howdy Doody Time » Wed Apr 10, 2019 12:12 pm

I love this forum - my first foray into Guitar Valve Amps, and I'm getting one to one tuition from experts. Thanks so much Dave and Wonks! :)
User avatar
Howdy Doody Time
Frequent Poster
Posts: 590
Joined: Sun Jan 18, 2009 1:00 am
Location: Huai Yai, Chon Buri, Siam
The only excuse we have for making music in the first place is to make it differently..vis-a-vis our own difference (Glenn Gould)

Re: Laney Iron Heart IRT 120H head problem

Postby ef37a » Wed Apr 10, 2019 6:22 pm

Howdy Doody Time wrote:I love this forum - my first foray into Guitar Valve Amps, and I'm getting one to one tuition from experts. Thanks so much Dave and Wonks! :)

There is one gitamp book I can recommend (many are crap) Valve pre amps for Guitar and Bass by Merlin Blencowe.
Yes there is SOME maths in it but you don't need Calculus (or I couldn't handle it!) just simple equations and graphs. You don't even need the little maths there is because Merlin gives lots of wee schematics with values and tables.

I DO wish he would buckle down and do power stages before I am totally ga-ga!

Dave.
ef37a
Jedi Poster
Posts: 11489
Joined: Mon May 29, 2006 12:00 am
Location: northampton uk

Re: Laney Iron Heart IRT 120H head problem

Postby Howdy Doody Time » Thu Apr 11, 2019 6:26 am

GOOD NEWS!! :)

The power valves arrived this morning from Lazada. I changed all four out for the new ones, powered up, and waited...


Now it's been running about half an hour, and it's quiet as a church mouse. No hiss, no hum and no pops.

The preamp valves will arrive about the 20th, but I'll just store those away.

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 for mismatches.

Anyway, I want to thank you all for responding, I've always been terrified of valve equipment but your advice and guidance has helped me sort that, and the amplifier out.

Much obliged :)

Dominic (HDT)
User avatar
Howdy Doody Time
Frequent Poster
Posts: 590
Joined: Sun Jan 18, 2009 1:00 am
Location: Huai Yai, Chon Buri, Siam
The only excuse we have for making music in the first place is to make it differently..vis-a-vis our own difference (Glenn Gould)

Re: Laney Iron Heart IRT 120H head problem

Postby ef37a » Thu Apr 11, 2019 6:51 am

Good stuff!
When the pre amp valves arrive I strongly suggest you make time to check them.
Just swap out the first valve, usually the most critical for noise and hum. Go through the batch that way and if any seem unduly noisy get back to the supplier. No good complaining 2 years down the line!

I am not surprised the valves "matched" pretty well, that was my experience with EL34s and EL84s. In any case, with 4 valves any differences are averaged out better than pairs.

BTW, keep the old OP valves. They are only ever going to get more expensive IMO and I bet three of them are perfectly ok!

You are right to be wary of valve gear! The stuff inside the chassis takes few prisoners. If people are really stuck I will tell them how to bias amps in a PM but not post the procedure.

Dave.
ef37a
Jedi Poster
Posts: 11489
Joined: Mon May 29, 2006 12:00 am
Location: northampton uk

Re: Laney Iron Heart IRT 120H head problem

Postby Wonks » Thu Apr 11, 2019 8:16 am

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!
User avatar
Wonks
Jedi Poster
Posts: 10881
Joined: Thu May 29, 2003 12:00 am
Location: Reading, UK
Correcting mistakes on the internet since 1853

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.
ef37a
Jedi Poster
Posts: 11489
Joined: Mon May 29, 2006 12:00 am
Location: northampton uk

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.
User avatar
Howdy Doody Time
Frequent Poster
Posts: 590
Joined: Sun Jan 18, 2009 1:00 am
Location: Huai Yai, Chon Buri, Siam
The only excuse we have for making music in the first place is to make it differently..vis-a-vis our own difference (Glenn Gould)

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.
User avatar
Wonks
Jedi Poster
Posts: 10881
Joined: Thu May 29, 2003 12:00 am
Location: Reading, UK
Correcting mistakes on the internet since 1853

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.
User avatar
Howdy Doody Time
Frequent Poster
Posts: 590
Joined: Sun Jan 18, 2009 1:00 am
Location: Huai Yai, Chon Buri, Siam
The only excuse we have for making music in the first place is to make it differently..vis-a-vis our own difference (Glenn Gould)

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.
User avatar
Howdy Doody Time
Frequent Poster
Posts: 590
Joined: Sun Jan 18, 2009 1:00 am
Location: Huai Yai, Chon Buri, Siam
The only excuse we have for making music in the first place is to make it differently..vis-a-vis our own difference (Glenn Gould)

Re: Laney Iron Heart IRT 120H head problem

Postby Allen Puckett » Wed Mar 18, 2020 3:41 am

Hey guys, please help! I have the Laney Ironheart 120. It recently started sounding distorted on the clean channel. It makes a clicking sounds even after I turn it off. Im worried I messed up the tubes or something. The tubes get orange dots on them, but I saw in a video of a guy demoing the amp, they were orange on his, too. So I figured it wasn't an issue. I had been using a boss metalzone pedal through the fx loop return jack. What did I mess up? How would I run a pedal through the pre amp without messing it up? Any input is greatly appreciated. I want to think I know what I'm doing, but I need some advice.
Allen Puckett
Posts: 1
Joined: Wed Mar 18, 2020 3:32 am

Re: Laney Iron Heart IRT 120H head problem

Postby ef37a » Wed Mar 18, 2020 2:21 pm

Hello Allen and welcome to SOS.
The Orange 'dots' are the weld points on the valve anodes ('plates' to the US peeps)

They should not be there as it indicates that the valves are dissipating more power than the specification states. Unfortunately some manufacturers run their valves so close to max spec that tolerances and a high mains voltage can push them into 'redplating', this will drastically shorten their lives. There is a following for the idea that valves MUST be run close to their limits for a good tone. BS IMHO and that of many top techs I talk to.

The fix is unfortunately not that simple. You need an amp tech, if the valves are 'fixed biased'* then they can have their anode current backed off (if there is a bias adjusting pot that is!) I suspect the 20 is 'cathode' biased and that means a slightly higher value cathode resistor. You could also find a different set of valves stay cooler but that is random.

In the normal course of events a pedal will not cause any damage to a decently designed valve amp. Maybe one of lesser quality might object if you drive the ***s off it for 3 hours?

*Fixed bias is usually adjustable. Cathode bias is fixed!

Dave.
ef37a
Jedi Poster
Posts: 11489
Joined: Mon May 29, 2006 12:00 am
Location: northampton uk

Re: Laney Iron Heart IRT 120H head problem

Postby Wonks » Wed Mar 18, 2020 3:34 pm

Unless you've swapped them over for EL34s, then the amp should come with 4 x 6L6 valves. However, the amp can be fitted with EL34s, and there is a bias switch on the back to select the valve type fitted. Just make sure that the switch hasn't got knocked and is still on the 6V6 setting.
User avatar
Wonks
Jedi Poster
Posts: 10881
Joined: Thu May 29, 2003 12:00 am
Location: Reading, UK
Correcting mistakes on the internet since 1853

Previous