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The John East preamp club

#423
Nuage420 said:
I broke the gain trim on my uni pre. The adjustment slots are made of a very soft plastic that marred and stripped out as I dialed in my tone. I love everything about this pre, I looked on the website and it doesn't seem I could just order that single part. Luckily it still works as passive but man what a bummer.
Click to expand...

Email John directly. Undoubtedly he will sort you out; his service is excellent.
 
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#424
My uni pre just arrived, can somone explain how the bass control works? How do these frequency selectors work? Do you boost two different frequencies in one knob? And what frequencies do you prefer to choose on the high/ low bass selectors?
 
#425
Borgenyorgen said:
My uni pre just arrived, can somone explain how the bass control works? How do these frequency selectors work? Do you boost two different frequencies in one knob? And what frequencies do you prefer to choose on the high/ low bass selectors?
Click to expand...

It should have come with some documentation. If not, it's available at John's website: UNI-PRE-01-4-KNOB-01-1.pdf
 
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#427
Borgenyorgen said:
Thanks! It did i just do not understand how it works, i know that you can change 2 bass frequencies on the board itself but you only have one knob to control them, so do they both change simultaneously?
Click to expand...
I think mine is the same as yours, just with an extras knob.
If that's true, the yours has a "bass window", which means you select the range of bass frequencies that are affected when you turn the knob.
Some folks like the bass to be around 40hz, some like it around 80, or even 100.
You set the range of those frequencies on the board, then you boost or cut them as need with the knob.
 
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#428
flojob said:
I think mine is the same as yours, just with an extras knob.
If that's true, the yours has a "bass window", which means you select the range of bass frequencies that are affected when you turn the knob.
Some folks like the bass to be around 40hz, some like it around 80, or even 100.
You set the range of those frequencies on the board, then you boost or cut them as need with the knob.
Click to expand...
Yeah, there are two "bass windows " though, does that mean i control two frequencies with one knob?
 

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#429
flojob said:
I think mine is the same as yours, just with an extras knob.
If that's true, the yours has a "bass window", which means you select the range of bass frequencies that are affected when you turn the knob.
Some folks like the bass to be around 40hz, some like it around 80, or even 100.
You set the range of those frequencies on the board, then you boost or cut them as need with the knob.
Click to expand...
Oh, i think i kinda get it, if i set it to 90-100 it affects all the frequency range between them? Thanks! Really took me a while to understand this lol
 
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#430
Nuage420 said:
I broke the gain trim on my uni pre. The adjustment slots are made of a very soft plastic that marred and stripped out as I dialed in my tone. I love everything about this pre, I looked on the website and it doesn't seem I could just order that single part. Luckily it still works as passive but man what a bummer.
Click to expand...

Send your inquiry to John East via email. It may take a couple of days for a response, but he'll tell you definitely whether or not you can get the part you are looking for.

It can probably be acquired from one of the parts houses such as DigiKey, Markertek, Mouser, or other supplier. With some serious detective work….
 
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#431
Very sorry to hear of this issue, since the slots are quite small and delicate it's important to use a suitable screwdriver and adjust very gently, controlling the screw between thumb and finger, for example. As soon as the end-stop is felt, stop any pressure, as this the point they can be damaged by trying to turn further.

It is possible to replace the gain trims but even if they are mechanically broken, active should carry on working,
even if the gain isn't set as you'd like.

We have the gain trimmer presets but I wouldn't recommend trying to change them yourself unless you are highly experienced in delicate soldering and repair.
 
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#432
Geri O said:
Send your inquiry to John East via email. It may take a couple of days for a response, but he'll tell you definitely whether or not you can get the part you are looking for.

It can probably be acquired from one of the parts houses such as DigiKey, Markertek, Mouser, or other supplier. With some serious detective work….
Click to expand...

Certainly, they are a common standard part type, many sources for them. I can find the part numbers.
 
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#433
John East said:
Very sorry to hear of this issue, since the slots are quite small and delicate it's important to use a suitable screwdriver and adjust very gently, controlling the screw between thumb and finger, for example. As soon as the end-stop is felt, stop any pressure, as this the point they can be damaged by trying to turn further.

It is possible to replace the gain trims but even if they are mechanically broken, active should carry on working,
even if the gain isn't set as you'd like.

We have the gain trimmer presets but I wouldn't recommend trying to change them yourself unless you are highly experienced in delicate soldering and repair.
Click to expand...

I am certainly not good with soldering, and apparently not much of anything that requires a delicate touch haha...

I have a local luthier who is though.
 
#435
John East said:
Certainly, they are a common standard part type, many sources for them. I can find the part numbers.
Click to expand...

Thanx for speaking into this, Mr East. The detective work I mentioned is more of the process of combing through hundreds of pages of parts in those catalogs and websites.

Part numbers most definitely and immensely speed up the process.

Still very much enjoying my J Retro preamp.
 
#436
John East said:
Ha-Ha, very good! But does the system work in active, still?

It should, even if a gain preset was damaged it should carry including if the gain presets weren't there.
Click to expand...
It does not work in active. The blue block bent as well. I get a very nasty hissing and when I play a note it clips and gets extremely loud swells. I had to quickly roll the volume off and disconnected the bass. Pulling to go passive makes all the nasty bosses stop then pushing back into active brought it back. I haven't pulled it out yet as it's my only bass at the moment and since it works fine in passive I let it be until I got replacement parts in or a new pre.
 

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