Difficult customer

[Phil Allison]

** Hi,

if you do guitar amp repairs for any time at all, you will likely come across someone like the guy in this Vid:

https://www.youtube.com/watch?v=ikIDYHna9Dc

His Fender Pro 185 ( 150watt rated with 2 x 12inch speakers ) has a small amount of background hum, plus a slight hum in the reverb. But that is NOT how he sees it.

Repairers can be expected to fix faults that develop, but something that has been that way since manufacture is another story - often being near impossible or uneconomic to fix.

The two repairers mentioned wisely chose not to waste time trying.



..... Phil

 

On Monday, 2 July 2018 01:33:05 UTC+1, Phil Allison wrote:

** Hi,

if you do guitar amp repairs for any time at all, you will likely come across someone like the guy in this Vid:

https://www.youtube.com/watch?v=ikIDYHna9Dc

His Fender Pro 185 ( 150watt rated with 2 x 12inch speakers ) has a small amount of background hum, plus a slight hum in the reverb. But that is NOT how he sees it.

Repairers can be expected to fix faults that develop, but something that has been that way since manufacture is another story - often being near impossible or uneconomic to fix.

The two repairers mentioned wisely chose not to waste time trying.



.... Phil

Many things are uneconomic, and some customers unreasonable. But fixing background hum from new is often an easy job. If the psu is unregulated, adding lf filtering sometimes sorts it. I used to like CDC filters, capacitor diode capacitor, the D acts as a low R nonlinear resistor. The upside is voltage drop is limited, and the filtering gets better as output volume drops. Of course hum can also be caused by a host of other things not as simple to fix.

Reminds me of the guitar amp that had had the wrong transformer fitted, giving twice the wanted voltage. Distorted & cut out often. A rework of the psu configuration sorted it. It's a lot easier if the transformer gives half the required voltage!


NT

 

[Phil Allison]

tabb...@gmail.com wrote:

Many things are uneconomic, and some customers unreasonable.
But fixing background hum from new is often an easy job.
If the psu is unregulated, adding lf filtering sometimes sorts it.
I used to like CDC filters, capacitor diode capacitor, the D acts
as a low R nonlinear resistor. The upside is voltage drop is limited,
and the filtering gets better as output volume drops.
Of course hum can also be caused by a host of other things not as
simple to fix.

** As the background hum in the Pro 185 is independent of control settings, I have a hunch that is due to magnetic field from the AC transformer infecting the earth/ground patterns on the PCB near it.




.... Phil

 

[Phil Allison]

Phil Allison wrote:

** As the background hum in the Pro 185 is independent of control
settings, I have a hunch that is due to magnetic field from the
transformer infecting the earth/ground patterns on the PCB near it.



**FYI:

https://en.audiofanzine.com/solid-state-combo-guitar-amp/fender/PRO-185/medias/pictures/a.play,m.898605.html

 

On Monday, 2 July 2018 10:42:55 UTC+1, Phil Allison wrote:

Phil Allison wrote:



** As the background hum in the Pro 185 is independent of control
settings, I have a hunch that is due to magnetic field from the
transformer infecting the earth/ground patterns on the PCB near it.



**FYI:

https://en.audiofanzine.com/solid-state-combo-guitar-amp/fender/PRO-185/medias/pictures/a.play,m.898605.html

I guess one could move it, but the cost/return ratio isn't looking good.


NT

 

[John Robertson]

On 2018/07/02 2:42 AM, Phil Allison wrote:

Phil Allison wrote:



** As the background hum in the Pro 185 is independent of control
settings, I have a hunch that is due to magnetic field from the
transformer infecting the earth/ground patterns on the PCB near it.



**FYI:

https://en.audiofanzine.com/solid-state-combo-guitar-amp/fender/PRO-185/medias/pictures/a.play,m.898605.html

That is industrial equipment, for use on stage. Not for home listening
levels. The hum is quite quiet compared to the volume of the unit that
it would be well within the original specs.

I have the same problem in my field. Our pinball games use industrial
style art, chrome, electronics, etc. They hum, whistle, rattle and make
all sorts of mechanical noises that may be a nuisance in the home, but
inaudible (relatively speaking) in an arcade - where the equipment was
designed to be used defines the minimum acceptable background noise levels.

Once I point that out most people are quite understanding!

John ;-#)#

 

Actually, that is the point. If the hum is at the same level no matter how loud it is set, it is simply not suitable for home use or whatever. There is such a thing as a power soak though that can cut the output itself down which would take the hum with it.

At the music store there was a discussion about fan noise, I said something to the effect that when you are on stage they never hear that, but when you are at home listening to Mozart or some shit, that is different.

Most people do not use a 150 watt amp to practice in the kitchen. That doesn't mean they are not assholes.

 

On Monday, 2 July 2018 23:59:06 UTC+1, jurb...@gmail.com wrote:

Actually, that is the point. If the hum is at the same level no matter how loud it is set, it is simply not suitable for home use or whatever. There is such a thing as a power soak though that can cut the output itself down which would take the hum with it.

At the music store there was a discussion about fan noise, I said something to the effect that when you are on stage they never hear that, but when you are at home listening to Mozart or some shit, that is different.

Most people do not use a 150 watt amp to practice in the kitchen. That doesn't mean they are not assholes.

It doesn't make them assholes either. It's the wrong attitude for a customer facing position.


NT

 

The solution is simple.

Figuring out what the engineers did wrong $ 150
Figuring out a solution $ 100
Implementing the solution $ 75
Putting up with an asshole $ 100.

Total $ 425, and if the math is wrong you pay it anyway. If you want a rush job double that. And it is $ 20 per phone call and $ 5 per email.

Plus all applicable taxes of course.

 

[John-Del]

On Sunday, July 1, 2018 at 8:33:05 PM UTC-4, Phil Allison wrote:

** Hi,

if you do guitar amp repairs for any time at all, you will likely come across someone like the guy in this Vid:

https://www.youtube.com/watch?v=ikIDYHna9Dc

His Fender Pro 185 ( 150watt rated with 2 x 12inch speakers ) has a small amount of background hum, plus a slight hum in the reverb. But that is NOT how he sees it.

Repairers can be expected to fix faults that develop, but something that has been that way since manufacture is another story - often being near impossible or uneconomic to fix.

The two repairers mentioned wisely chose not to waste time trying.



.... Phil

Well, at least the youtuber didn't trash the two repairers who looked at it.

One should never believe a technician who has been doing repairs for decades, but if it's on the internet, it must be true. Therefore...

The commenters below the video probably convinced him that the noise he's complaining about is part and parcel for that type of amp.

 

[Gareth Magennis]

"John-Del" wrote in message
news:521a626b-b8bf-4cff-a72e-7c122cc62d86@googlegroups.com...

On Sunday, July 1, 2018 at 8:33:05 PM UTC-4, Phil Allison wrote:

** Hi,

if you do guitar amp repairs for any time at all, you will likely come
across someone like the guy in this Vid:

https://www.youtube.com/watch?v=ikIDYHna9Dc

His Fender Pro 185 ( 150watt rated with 2 x 12inch speakers ) has a small
amount of background hum, plus a slight hum in the reverb. But that is NOT
how he sees it.

Repairers can be expected to fix faults that develop, but something that
has been that way since manufacture is another story - often being near
impossible or uneconomic to fix.

The two repairers mentioned wisely chose not to waste time trying.



.... Phil

Well, at least the youtuber didn't trash the two repairers who looked at it.

One should never believe a technician who has been doing repairs for
decades, but if it's on the internet, it must be true. Therefore...

The commenters below the video probably convinced him that the noise he's
complaining about is part and parcel for that type of amp.





******************************

I think the customer's main beef is the amp is too noisy to record.

Now, it could actually turn out to be this customer does not know how to
record a typically noisy combo, and this is all a bit of a red herring.


He might be needlessly compressing the f**k out of it, which raises the
noise floor by the amount of compression applied.
You are REALLY going to hear that hum now.


Whatever, I think the customer doesn't have much of a clue about what he
has, and how best to use it.


Gareth.

 

>"Whatever, I think the customer doesn't have much of a clue about what he has, and how best to use it."

Tell me about it, god damn, people are clueless.

When I worked at the music store a couple years ago, they had a digital effects box. this is meant to go in the effects loop of an amp or a mixer. they had it right between the guitar and the amp. HELLO, this thing is designed to operate on 300 or 400 mV, not TWO that you are giving it !

Also, with idiots like that in the field of music, Âź" soewaker cables should be outlawed. A speaker cable is used on the input from the guitar to amp and they wonder why it hums. And then a shielded cable designed for low level, they plug a speaker into a 400 watt amp with it and wonder why it goes bad.

There's more, they had a little band, actually not bad, but the guy decided he wanted a speaker switcher on these two amps, one was BTL and the other wasn't. Blew the breaker in the wall. Yeah - "I never connected them together". Well then how come we got blown outputs in both and they blew the main circuit before the internal AC fuses blew ?

One time they could tell I drank the night before, and I mean drank. I wasn't feeling all that great, not a hangover but kinda close. so I go to say my goodbyes at the end of the day and the boss says "Get you to a bar immediately". Well he had a heart attack and is dead and I am alive, and he was about ten years younger than I. So there. Rot. Meantime I will be well preserved. LOL

Phil likes to fuck with me but so what ? I know what the fuck I am doing and nobody can take that away. They are fixing my eyes this year and I am getting my resume' or CV whatever ready. If nobody bites I will start my own enterprise, and then pay zero taxes. HAHA.

I was in very bad physical shape but that is changing. They told me I almost died after the injury, but I didn't. Almost died is my middle name and I will be baack.

At any rate, people are so clueless, they'll plug a magnetic cartridge into a tape loop and wonder why it is not loud enough, and a tuner into the phono and wonder why it is so muffled and distorted.

Seems to me if you had a way to dispose of the bodies...

 

[KenW]

On Sat, 7 Jul 2018 22:20:21 +0100, "Gareth Magennis"
<soundserviceleeds@outlook.com> wrote:

"John-Del" wrote in message
news:521a626b-b8bf-4cff-a72e-7c122cc62d86@googlegroups.com...

On Sunday, July 1, 2018 at 8:33:05 PM UTC-4, Phil Allison wrote:
** Hi,

if you do guitar amp repairs for any time at all, you will likely come
across someone like the guy in this Vid:

https://www.youtube.com/watch?v=ikIDYHna9Dc

His Fender Pro 185 ( 150watt rated with 2 x 12inch speakers ) has a small
amount of background hum, plus a slight hum in the reverb. But that is NOT
how he sees it.

Repairers can be expected to fix faults that develop, but something that
has been that way since manufacture is another story - often being near
impossible or uneconomic to fix.

The two repairers mentioned wisely chose not to waste time trying.



.... Phil


Well, at least the youtuber didn't trash the two repairers who looked at it.

One should never believe a technician who has been doing repairs for
decades, but if it's on the internet, it must be true. Therefore...

The commenters below the video probably convinced him that the noise he's
complaining about is part and parcel for that type of amp.





******************************

I think the customer's main beef is the amp is too noisy to record.

Now, it could actually turn out to be this customer does not know how to
record a typically noisy combo, and this is all a bit of a red herring.


He might be needlessly compressing the f**k out of it, which raises the
noise floor by the amount of compression applied.
You are REALLY going to hear that hum now.


Whatever, I think the customer doesn't have much of a clue about what he
has, and how best to use it.


Gareth.

Sounds like 60 cycles. Solid state should be easy to find source. I
would use my telephone test set to find that !

 

[Phil Allison]

John-Del wrote:

Phil Allison wrote:
** Hi,

if you do guitar amp repairs for any time at all, you will likely come across someone like the guy in this Vid:

https://www.youtube.com/watch?v=ikIDYHna9Dc

His Fender Pro 185 ( 150watt rated with 2 x 12inch speakers ) has a small amount of background hum, plus a slight hum in the reverb. But that is NOT how he sees it.

Repairers can be expected to fix faults that develop, but something that has been that way since manufacture is another story - often being near impossible or uneconomic to fix.

The two repairers mentioned wisely chose not to waste time trying.



.... Phil


Well, at least the youtuber didn't trash the two repairers who looked at it.

** He kinda did really - suggesting they must be deaf not to hear the obvious ( to him) humming.

FYI: The Fender Pro 185 has a FET muting circuit which opens when a jack is plugged into the input - that is why he plugged in a lead, fingering the tip to get some hum.

I also wondered for a minute if the power is that room might be missing its earth link.

Anyhow, I posted the vid so folk could observe the typical whiny attitude of these "never happy" kind of guys.


..... Phil

 

On Saturday, July 7, 2018 at 9:21:09 PM UTC-4, Phil Allison wrote:

John-Del wrote:

Phil Allison wrote:
** Hi,

if you do guitar amp repairs for any time at all, you will likely come across someone like the guy in this Vid:

https://www.youtube.com/watch?v=ikIDYHna9Dc

His Fender Pro 185 ( 150watt rated with 2 x 12inch speakers ) has a small amount of background hum, plus a slight hum in the reverb. But that is NOT how he sees it.

Repairers can be expected to fix faults that develop, but something that has been that way since manufacture is another story - often being near impossible or uneconomic to fix.

The two repairers mentioned wisely chose not to waste time trying.



.... Phil


Well, at least the youtuber didn't trash the two repairers who looked at it.


** He kinda did really - suggesting they must be deaf not to hear the obvious ( to him) humming.

FYI: The Fender Pro 185 has a FET muting circuit which opens when a jack is plugged into the input - that is why he plugged in a lead, fingering the tip to get some hum.

I also wondered for a minute if the power is that room might be missing its earth link.

Anyhow, I posted the vid so folk could observe the typical whiny attitude of these "never happy" kind of guys.


.... Phil

These are the types of guys that would comment on the sound of their band to me at the board. I would usually direct them to an unused channel to adjust. Each time the "adjustment" would make a difference to the sound of the band. pretty amazing for an unconnected channel...

 

[Phil Allison]

Gareth Magennis wrote:

The commenters below the video probably convinced him that the noise he's
complaining about is part and parcel for that type of amp.



I think the customer's main beef is the amp is too noisy to record.

** I used to get that BS a lot once from incompetent studio "engineers".

Dynamic mics were often pushed up against the grille cloth of a cab ( live sound reinforcement style ) and significant hum then heard in the control room monitoring.

Fact often was the amp did not audibly hum at all - the mic ( usually a Shure 57 or 58) was picking up supply frequency mag field from the amp's power transformer.

Any dynamic mic's voice coil alone can do this plus 57s & 58s have *unshielded* matching transformers in the handle that do an even better job.

Whatever, I think the customer doesn't have much of a clue about what he
has, and how best to use it.

** Correct.


...... Phil

 

[Phil Allison]

Gareth Magennis wrote:

The commenters below the video probably convinced him that the noise he's
complaining about is part and parcel for that type of amp.



I think the customer's main beef is the amp is too noisy to record.

** I used to get that BS a lot once from incompetent studio "engineers".

Dynamic mics were often pushed up against the grille cloth of a cab ( live sound reinforcement style ) and significant hum then heard in the control room monitoring.

Fact often was the amp did not audibly hum at all - the mic ( usually a Shure 57 or 58) was picking up supply frequency mag field from the amp's power transformer.

Any dynamic mic's voice coil alone can do this plus 57s & 58s have *unshielded* matching transformers in the handle that do an even better job.

Whatever, I think the customer doesn't have much of a clue about what he
has, and how best to use it.

** Correct.


...... Phil