• TalkBass has been independent since 1998. Add your voice.
    Create a free account to reply to discussions, view embedded media, and browse with fewer display ads.
    Join free Log in
    Want zero display ads or expanded classifieds tools? Compare plans.

Mesa Boogie Walkabout Mega-thread Part 10

#1,821
Well guys, I have an update. As per my last post I was having issues with thermal shutdown on the Wlkbt, I sent it to Mesa and it turns out that the fan mod that the previous owner did on it was culprit, the silex fan was simply inadequate to cool the unit. As such I'd caution against modding the head. (Your mileage may vary, but I was informed that the mod was a common issue that merits repair)
In other news, I've found the solution to extracting maximum clean volume from the unit...
image.jpeg
 
  • Like
Reactions: Jhonnybass, lomo, Aaron Mc and 2 others
#1,823
gillento said:
My 12" Scout Combo as developed some noise on the speaker side (tried it with 2 different amps).
is there a replacement driver available?

I live in Luxembourg, Europe and the local distributor/service centre isn't very helping in the matter.
Click to expand...

You can order replacement speakers from the Mesa website; I'm not sure if they ship internationally, but I would assume they do.
 
#1,824
gillento said:
My 12" Scout Combo as developed some noise on the speaker side (tried it with 2 different amps).
is there a replacement driver available?

I live in Luxembourg, Europe and the local distributor/service centre isn't very helping in the matter.
Click to expand...
It's an OEM version of the Eminence Deltalite II speaker. I had a non-OEM version in one of my old Scouts and couldn't hear any dramatic difference! I'd also suspect the crossover/tweeter assembly if you're having noise issues. What is the noise like?
 
#1,825
punchdrunk said:
Well guys, I have an update. As per my last post I was having issues with thermal shutdown on the Wlkbt, I sent it to Mesa and it turns out that the fan mod that the previous owner did on it was culprit, the silex fan was simply inadequate to cool the unit. As such I'd caution against modding the head. (Your mileage may vary, but I was informed that the mod was a common issue that merits repair)
In other news, I've found the solution to extracting maximum clean volume from the unit...
View attachment 923076
Click to expand...
Are you sure you had the correct model of Silenx fan in there? I installed one in my WA a year or so ago and have not had issues. While I understand that changing the fan could void the warranty, I wonder if @agedhorse might dare to weigh in on this topic.

The model I installed is this one, which I thought provides equal or greater CFM than the stock fan:

https://www.amazon.com/gp/product/B005ZF64TQ/ref=oh_aui_search_detailpage?ie=UTF8&psc=1
 
As an Amazon Associate, TalkBass may receive commissions from qualifying purchases made via links on this site.
#1,826
I can't say for sure, but in general (for non-speed controlled fans) it's important to match the terminal voltages and CFM at the same rated static pressure. Otherwise the actual air flow will be different. It's even more complicated for variable speed fans, as there is a current versus static pressure versus air flow curve set that needs to be matched up as well.

This is why I caution against making modifications without understanding the intent as well as the details of the original design, ESPECIALLY some of the new low noise design approaches.
 
  • Like
Reactions: punchdrunk
#1,827
agedhorse said:
I can't say for sure, but in general (for non-speed controlled fans) it's important to match the terminal voltages and CFM at the same rated static pressure. Otherwise the actual air flow will be different. It's even more complicated for variable speed fans, as there is a current versus static pressure versus air flow curve set that needs to be matched up as well.

This is why I caution against making modifications without understanding the intent as well as the details of the original design, ESPECIALLY some of the new low noise design approaches.
Click to expand...
Thanks for jumping in, Andy. And speaking of "new low noise design approaches" I really appreciate the fan noise level (or lack thereof) from my new D800. Great job there.
 
#1,828
Fan noise involves a lot more than just choosing a fan. There are low noise fan blades, bearings (ball bearing fans tend to be louder, but not always), aerodynamic approaches to the venting, speed controls (but the fan control circuit must sense the proper locations within the amp), even things like the thickness of the fan versus the blade profile is important. Then, the air must flow properly over the necessary parts of the circuit being cooled, the feedback of the controls must have reasonable proportional control (ie. no undesirable lag, and certainly no hunting), and on-off control is a particular no-no because of the ear's sensitivity to stepped noise sensitivity. Designers of control systems will understand why this stuff is so important.
 
  • Like
Reactions: Al Kraft
#1,829
image.jpg
This is the culprit. Also, the 3rd wire creates resistance further diminishing its cpm value. (I was told that by Mesa)... I don't know jack about electronics, but I'd be inclined to bend an ear to sage cats like agedhorse when it comes to such matters.
 
#1,830
I have used my Walkabout Scout in theater productions and in pit orchestras many times without any noise issues at all. Often sections of a show will be very quiet.... My blackface Walkabout is 100% STOCK .. It if doesn't bother anyone in a quiet situation like that then i don't know how it could bother anyone on gigs where there are louder drums and vocal etc. If it ain't broken, don't fix it . IMO
 
  • Like
Reactions: Caca de Kick
#1,831
Some 3 wire fans use the third wire as a tach feedback, some for temperature sensing, and some include a temperature sensor within the fan itself. It's essential to understand the differences and fundamentally how it all works.
 
#1,832
punchdrunk said:
View attachment 923414 This is the culprit. Also, the 3rd wire creates resistance further diminishing its cpm value. (I was told that by Mesa)... I don't know jack about electronics, but I'd be inclined to bend an ear to sage cats like agedhorse when it comes to such matters.
Click to expand...
That's the same fan I had installed in my WA. Just got home from a gig with it and no problems (as usual). I did have mine installed by a tech and I remember he told me he did something in regards to the third wire (which I can no longer remember).
 
#1,834
svtb15 said:
I have used my Walkabout Scout in theater productions and in pit orchestras many times without any noise issues at all. Often sections of a show will be very quiet.... My blackface Walkabout is 100% STOCK .. It if doesn't bother anyone in a quiet situation like that then i don't know how it could bother anyone on gigs where there are louder drums and vocal etc. If it ain't broken, don't fix it . IMO
Click to expand...

Agreed. I have (another) early silver/red faced WA. The only time I hear the fan is when I'm by myself at home. Even when I arrive at a venue before anyone else and set up my rig, I can never hear the fan in any venue I've been in.
 
  • Like
Reactions: svtb15
#1,835
mikeswals said:
Agreed. I have (another) early silver/red faced WA. The only time I hear the fan is when I'm by myself at home. Even when I arrive at a venue before anyone else and set up my rig, I can never hear the fan in any venue I've been in.
Click to expand...
I don't think they are all the same. My silver face had the loudest fan of any electronic device I've ever owned. That includes several lead sled power amps. It was audible over acoustic jams and noticeable on electric gigs between songs. Other musicians commented on it. It bothered me. So I did the mod. I had never done a mod to an amp before but this seems to be working out fine. No issues after several years.
 
#1,836
mine too! After some research I have come to the conclusion that if I want the same cooling than the stock Sunon fan I have to choose a high speed-high noise replacement. Just about every silent fan has low rpm and cooling capability, there is no escape for this. Even the Sunon silent models do achieve these results with low rpm.
I think that I may just see if the amp starts to cut out in a 8 ohm load, and proceed from there.
My Noctua NF8 is as silent as it can be but only 1800 rpm and 31 cfm, in order to obtain 40-46 cfm a 3000 rpm fan is needed, at double the db measure, much much louder. Hope there is no need to going back, I perform a lot of studio desk work, and the stock fan was so loud to interfere with monitoring and just about every studio procedure
 

Latest posts

Top Bottom
Back