Mark IIC Cooling Fan.

[Nick Athanasatos]

Hi.. Ive read that there is a quieter up grade fan for the original fan in the Mark IIC Combo
I wouldn't be maybe looking to change it but the wire that connects the amp head inside there
keeps disconnecting from the fan and has to be held in with electric tape as the pin connection is so just barely holding.
Because of this I noticed the fan a bit noisy.
The other question is this and attached to the lower removable panel and something in cabinet cause I can't pull lower
back panel off after removing screws ? Thanks

 

[Nick Athanasatos]

No one seems to want to chime in on the Mark IIC Cooling Fan. So I am responding to myself.
Had Mark IIC Converted to C+ and they sent me a new fan cause the plug keeps falling out of the
original Howard Fan mainly and I thought in new technology a quieter fan could be had..WRONG.
This new fan made in China is quiet but reason seems to be it blows a fraction of the air of the original !! : (
Oh brother..it really is a fan in name only. The old one can cool your face, this thing is nothing.
I don't recommend that fan if you are ever in need of another one.
I once had that original Howard fan unplugged as it fell out..
and the whole amp was so freakin hot I thought it would be permanently damaged. Way too hot.
So Im going to reinstall the original fan and put a dot of strong glue on there and supplement it with electric tape.
What a hassle. Trying to call Mesa Boogie and they never answer phone until later and all of my
Mike Bendinelli emails seem to have all disappeared.

 

[FedWar]

Hey,
I've bought at least four fan of this model
Which is sold from the US.

https://www.digikey.it/en/products/detail/orion-fans/OA109AP-11-3TB/2620912

I've checked the specs and they are almost identical to the Howard one.

This is my number one recommendation

 

[Theresa]

Clean the general contact area and plug. Apply silicone to the installed plug area. Wait for the silicone to cure. Fixed. The silicone can be removed without a mess, unlike tape. It will withstand temperatures. It is non-conductive.If the fan is still operational and just noisy, it could just need a deassembly and a good cleaning. Lubricate the critical parts before reassembly. Best of luck!

 

[scotticus]

Genuine question, are you assuming that the replacement fan is not blowing as much air because the fan it so much quieter than the original? Just trying to understand because I've purchased one of the Mesa replacement fans long ago but not installed it yet, but the fan itself is quite heavy and sturdy and the blades spin effortlessly, so I assumed once plugged in, it would be a dead silent perfect replacement.

 

[FedWar]

Genuine question, are you assuming that the replacement fan is not blowing as much air because the fan it so much quieter than the original? Just trying to understand because I've purchased one of the Mesa replacement fans long ago but not installed it yet, but the fan itself is quite heavy and sturdy and the blades spin effortlessly, so I assumed once plugged in, it would be a dead silent perfect replacement.

FYI mesa doesn't sell replacement for old and bigger mark ii/iii/iv, they only sell the smaller one. (If I remember correctly)
And you can compare specs of both to check for rpm, noise and airflow

 

[scotticus]

FYI mesa doesn't sell replacement for old and bigger mark ii/iii/iv, they only sell the smaller one. (If I remember correctly)
And you can compare specs of both to check for rpm, noise and airflow

Yes, they sell the full size fan replacement for the early Mark series amps.

 

[FedWar]

Yes, they sell the full size fan replacement for the early Mark series amps.

https://store.mesaboogie.com/products/fan-783152-4-inch-115-vac-50-60hz-6-5-5-watts-globe.html

Ok, Saw that and forgot about it.
Mesa however won't sell outside the US and it is unobtanium in the EU, that is why I had to find an alternative.

The recommended orion fan has same specs in rpm noise and cfm of the original howard and can be also bought in the EU (and US as well).

 

[Nick Athanasatos]

Apologies..I was just cranky about the fan
and crushed my finger trying to put power section in.
Molly got back to me she is ultra nice and Mike B resent me all our communication that disappeared.
I was going to put the old fan back in but I changed my mind for a couple of reasons.
When I put the original Howard fan in same spot with the reverb packet under it the same distance it pushes much less air as when it is out in the open but still noticeably more than the Globe China new replacement. And the Howard much more noisier. I went up stairs to hear my Mark IV and it has a Howard fan too and that one is much quieter. So I decided to keep the new weaker Globe replacement in there and see how the over all thing heats up. So at moderate volume at home seems not overly hot if I decide to play at loud levels I'll put a small Vornado fan behind the amp.
If the little L brackets had a half inch more lift on that half maybe it would have more breeze.Anyway..for now cool.Ive connected reverb in wrong plug so will get in there and put it right and play it again soon.
The Orion Taiwan fan looks like the Globe fan..I don't know what any of these is in CFM.

 

[scotticus]

Ok I think I found an accurate data sheet on the Globe replacement fan. It's part A47-B15A-15T1-100. It's supposed to flow 49 CFM at 1450 RPM. I found this data on multiple websites, so it seems trustworthy.

The company that made the original fans seems to be long out of business, but I will say that the Cyclohm fans in my MkII and MkIII look absolutely identical but have slightly different part numbers. The fan in my MkII is as loud as a box fan, but will blow air in my face 6 feet off the ground. The fan in my MkIII is the same, except drastically quieter. There are several Cyclohm fans listed on eBay, and might be worth taking a shot on as long as the part number is different than the one in your MkII.

 

[Nick Athanasatos]

Ok I think I found an accurate data sheet on the Globe replacement fan. It's part A47-B15A-15T1-100. It's supposed to flow 49 CFM at 1450 RPM. I found this data on multiple websites, so it seems trustworthy.

The company that made the original fans seems to be long out of business, but I will say that the Cyclohm fans in my MkII and MkIII look absolutely identical but have slightly different part numbers. The fan in my MkII is as loud as a box fan, but will blow air in my face 6 feet off the ground. The fan in my MkIII is the same, except drastically quieter. There are several Cyclohm fans listed on eBay, and might be worth taking a shot on as long as the part number is different than the one in your MkII.

Yes the older Mark llC Combo Howard fan is much noiser than the Howard fan in my Mark lV Combo.I wonder what CFM on those were.

 

[FedWar]

Yes the older Mark llC Combo Howard fan is much noiser than the Howard fan in my Mark lV Combo.I wonder what CFM on those were.

google has the answer:

Howard 3-15-2470 specs
https://aerospace-electrical.com/air-circulator-equipment/tubeaxial-fan/3-15-2470

orion equivalent specs

globe motors

As you can see orion seems quieter and more efficient than globe motors

I've replaced my noisy and grindy howard fan with those in many mark (IIB, IIC, III and IV rev A) and I am more than happy so far.