Lemonade Drive report

[Mark]

I have my board at the stage where all the parts are in and I can listen to it.

It nails the sound Page gets. However, I found myself thinking it didn’t have enough bass so I replaced the 2.2uF bypass caps with 4.7uF caps as recommended here. Thanks for the tip by the way.

I wasn’t fond of the 100K log filter pot at the input, the cut end is pretty bunched up. I put a linear pot in and liked it better.

I’m thinking that I would like more range in the bass cut, maybe a 470 or 1000pF?

I was thinking the same thing about the treble response. There is a 3.3nF cap to earth shunting highs. That too could have a pot to add more highs. I think it would be too raspy without the cap, but the right value pot might be a good thing.

Any thoughts?

Regards

Mark

 

[music6000]

I have my board at the stage where all the parts are in and I can listen to it.

It nails the sound Page gets. However, I found myself thinking it didn’t have enough bass so I replaced the 2.2uF bypass caps with 4.7uF caps as recommended here. Thanks for the tip by the way.

I wasn’t fond of the 100K log filter pot at the input, the cut end is pretty bunched up. I put a linear pot in and liked it better.

I’m thinking that I would like more range in the bass cut, maybe a 470 or 1000pF?

I was thinking the same thing about the treble response. There is a 3.3nF cap to earth shunting highs. That too could have a pot to add more highs. I think it would be too raspy without the cap, but the right value pot might be a good thing.

Any thoughts?

Regards

Mark

What voltage are you getting on the Drain on 2n5457?
The original uses a Trimmer!

 

[Mark]

Good call M6000, the VDD is 8.35VDC on the battery that I’m using and the voltage on the drain is 6.97VDC.

I do have a 10K pot. I can remove the 6.8K and sub the pot in to determine the correct resistor value.

I assume the idea is to have half the rail voltage on the Drain.

I will give that a go. I don’t imagine the timbre will change, but there will be more headroom.

Regards

Mark

 

[Mark]

Okay, I removed the resistor and used the 10K pot. It wasn’t even close to being half the rail. I end up using a 100K trim pot and at about 19K (will have to double check) I had half the rail on the drain.

I played through the pedal and it was much the same sounding as far as I can remember, though the response of the filter pot was now exactly opposite where there was now too much bass cut and not enough bass on the rotation of the pot.

I will put the log pot back in, though I like the idea of being able to add more treble to response of the pedal.

Thanks again for your help.

Regards

Mark

 

[music6000]

Okay, I removed the resistor and used the 10K pot. It wasn’t even close to being half the rail. I end up using a 100K trim pot and at about 19K (will have to double check) I had half the rail on the drain.

I played through the pedal and it was much the same sounding as far as I can remember, though the response of the filter pot was now exactly opposite where there was now too much bass cut and not enough bass on the rotation of the pot.

I will put the log pot back in, though I like the idea of being able to add more treble to response of the pedal.

Thanks again for your help.

Regards

Mark

One would have to question if your 2N5457 is legit, I dialed mine @ 4.5v = 7K6!

 

[Mark]

One would have to question if your 2N5457 is legit, I dialed mine @ 4.5v = 7K6!

Well, 7.6K is very close to the stock 6.8K, so that makes sense.

I disconnected one side of the pot and the drain resistor is 20K which is quite a bit higher.

Here is photo of the 2N5457 in the board.



Thanks for your assistance.

Regards

Mark

 

[Mark]

This is the board, it still has to be cleaned etc.



Regards

Mark

 

[music6000]

Bass guitar FET preamp

Which first stage FET voltage drops by 50mV? You are welcome to fiddle with the Source resistors if you must(!), but I wouldn't. We're already substantially impaired trying to do this kind of work with no oscilloscope, and you already have the gain that you want (remember, Drain-res/Source-res...

www.diyaudio.com

Scroll down until you come to this:


Did you get it of ebay? ********
Do you have any way of testing to see if it is genuine.

 

[Mark]

I bought the 2N5457 from Pedal Parts Australia. I don’t know where these guys got them from. So are you saying they are duds?

Who is a recommended seller?

I haven’t read the whole thing yet as it’s a bit long winded.

Regards

Mark

 

[music6000]

Another bogus seller!

 

[Mark]

Thanks I’ll remember that.

Regards

Mark

 

[Feral Feline]

Another bogus seller!


View attachment 13852

Just to clarify, crystal-like, you're just saying FXI Electronics is a junk peddler, that "Another bogus seller!" was NOT a response to the previous post's mention of Pedal Parts Australia...?

 

[Mark]

I would like to point out that I have used Pedal Parts Australia before and I have found them to be very good to purchase from. I think Music6000 was referring to pop up eBay sellers.

The issue here is FET’s. It seems quite a few people have had issues with FETs judging by the links in this thread.

What are your thoughts on FET’s and the results I have?

I had thought of contacting PPA, but it’s not his problem really. He does sell a kit for a Dr Boogie, and may be able to offer some advice, but I’d like to know the right questions first.

Regards

Mark

 

[twebb6778]

I've only ever had good experiences with Pedal Parts Australia, their parts have always been legit and decent prices too.

 

[Mark]

I've only ever had good experiences with Pedal Parts Australia, their parts have always been legit and decent prices too.

But what is your take on the FET in my Lemonade board?

PPA isn’t the issue.

Regards

Mark

 

[music6000]

Just to clarify, crystal-like, you're just saying FXI Electronics is a junk peddler, that "Another bogus seller!" was NOT a response to the previous post's mention of Pedal Parts Australia...?

Like Tayda, Pedal Parts Australia get supplies from China, they have Good components & they have bad components.
If I see a 2N5457 with BC27 code, I would guantee it's a Fake!
About the only safe 2N5457 now is the Mouser Lead free version!

 

[Mark]

Music6000 could you provide a link to this part so I don’t order the wrong part?

I hate ordering from Mouser as the postage is expensive.

Thanks again to those offering assistance.

Regards

Mark

 

[Mark]

This is what I was seeing when testing the 2N5457. It doesn’t seem terribly meaningful though.

Any thoughts?




Regards

Mark

 

[music6000]

This is what I was seeing when testing the 2N5457. It doesn’t seem terribly meaningful though.

Any thoughts?

View attachment 13892
View attachment 13893

Regards

Mark

That is standard with this model for jfets.
It is a jfet you have but with the the most repetitive Batch number on the Internet, who knows if it is a genuine 2n5457 which is out of spec.
As you reported, you could not get half the voltage with a 10k pot & 6K8 is fixed value so it is a Fake or out of spec jfet!
This has been a common fault with 2N5457 & J201 being phased out!

 

[music6000]

Read my report & update on this Build from nearly 2 years ago :

M800 Overdrive

Awesome JCM800 Emulation !!! All the Trimmers were adjusted to 4.5v & it was meh, 4.75, 5v, 5.25v & 5.5v, Louder with no Gain! Old School, Strummed a Chord & tuned each Trimmer by ear. Critical Trimmer is the Tone trimmer, This effects overall EQ & gives it the Power of The JCM800 sizzle! The...

forum.pedalpcb.com