New 183 build

Overdrive Special, Steel String Singer, Dumbleland, Odyssey, Winterland, etc. -
Members Only

Moderators: pompeiisneaks, Colossal

Post Reply
User avatar
ijedouglas
Posts: 776
Joined: Fri Sep 22, 2017 9:07 pm
Location: Southern California

Re: New 183 build

Post by ijedouglas »

WhopperPlate wrote: Fri Sep 23, 2022 9:57 pm
Stephen1966 wrote: Fri Sep 23, 2022 8:31 pm

The LCA is a find! But only 220k, and yet rohs compliant. Makes me think that these are reissues and it could herald a new line in the works.
Until then , a few more bulk orders for everyone to pitch in on !
The new LCA's sound dull and lifeless. You also want to get the LCA 0411 instead of the 0414. The 0411 is the same(ish) as the q-line.

I have had some good success with the following:https://www.ebay.com/itm/264829123559
Ian
WhopperPlate
Posts: 1127
Joined: Fri Apr 16, 2010 9:04 am
Location: Santa Cruz, CA

Re: New 183 build

Post by WhopperPlate »

ijedouglas wrote: Sat Sep 24, 2022 2:41 am
WhopperPlate wrote: Fri Sep 23, 2022 9:57 pm
Stephen1966 wrote: Fri Sep 23, 2022 8:31 pm

The LCA is a find! But only 220k, and yet rohs compliant. Makes me think that these are reissues and it could herald a new line in the works.
Until then , a few more bulk orders for everyone to pitch in on !
The new LCA's sound dull and lifeless. You also want to get the LCA 0411 instead of the 0414. The 0411 is the same(ish) as the q-line.

I have had some good success with the following:https://www.ebay.com/itm/264829123559
Thanks for the heads up !
Charlie
User avatar
bepone
Posts: 1669
Joined: Mon Mar 09, 2009 4:22 pm
Location: Croatia
Contact:

Re: New 183 build

Post by bepone »

WhopperPlate wrote: Fri Sep 23, 2022 10:29 pm We keep our financial affairs separate …unsurprisingly she’s generally a bit more prepared for a rainy day lol
this is how it should be! and pile of vintage amplifiers under the bed is increasing surprisingly! :P
Stephen1966
Posts: 1017
Joined: Sun Nov 03, 2019 1:53 pm
Location: Czech Republic
Contact:

Re: New 183 build

Post by Stephen1966 »

bepone wrote: Sat Sep 24, 2022 7:34 am
WhopperPlate wrote: Fri Sep 23, 2022 10:29 pm We keep our financial affairs separate …unsurprisingly she’s generally a bit more prepared for a rainy day lol
this is how it should be! and pile of vintage amplifiers under the bed is increasing surprisingly! :P
Haha - really drifting off-topic now :lol:

I have a serious question, more a mini-dilemma and I just want to double check this with you. The schematic from jaysg (cca. 2010) only shows the FET circuit in a block diagram. The '100W in the style of #183' from mdroberts1243 outlines the FET and apart from a difference in value of the bias resistor (Rs) this looks identical to the Bluesmater FET.
Bluesmaster FET.jpg
But both of these are different again from the FET in the 124, which I have built and which I can confirm works fine. Although, I did finally reduce the filter cap there from 100uF to 47uF. I'm thinking I can use the same circuit again, only with the 47uF and a substitution of the 100pF X5F ceramic cap for a mica. I make my own PCBs but I guess Martin's boards would work fine there.

Is there any controversy there? Do I have my facts straight?
You do not have the required permissions to view the files attached to this post.
Stephen
www.primatone.eu
WhopperPlate
Posts: 1127
Joined: Fri Apr 16, 2010 9:04 am
Location: Santa Cruz, CA

Re: New 183 build

Post by WhopperPlate »

All the info you ever could want :

https://ampgarage.com/forum/viewtopic.php?t=18389

Mica vs ceramic certainly falls under the category of personal preference.
Charlie
User avatar
bepone
Posts: 1669
Joined: Mon Mar 09, 2009 4:22 pm
Location: Croatia
Contact:

Re: New 183 build

Post by bepone »

Stephen1966 wrote: Sat Sep 24, 2022 8:28 am
I have a serious question, more a mini-dilemma and I just want to double check this with you. The schematic from jaysg (cca. 2010) only shows the FET circuit in a block diagram. The '100W in the style of #183' from mdroberts1243 outlines the FET and apart from a difference in value of the bias resistor (Rs) this looks identical to the Bluesmater FET.

Bluesmaster FET.jpg

But both of these are different again from the FET in the 124, which I have built and which I can confirm works fine. Although, I did finally reduce the filter cap there from 100uF to 47uF. I'm thinking I can use the same circuit again, only with the 47uF and a substitution of the 100pF X5F ceramic cap for a mica. I make my own PCBs but I guess Martin's boards would work fine there.

Is there any controversy there? Do I have my facts straight?
100pf ceramic ok,
47-100uf no difference
FETs are all different also from the same series, you need to do biasing, with resistor Rs - source resistor.
90% you need to adjust something, so instead of Rs put some trimmer on wires and after adjusting you can put resistor. You can bias hot , middle or cold. Interesting FET circuit with cheap j201 is working very nice, you can make also drive stage biasing it..
Stephen1966
Posts: 1017
Joined: Sun Nov 03, 2019 1:53 pm
Location: Czech Republic
Contact:

Re: New 183 build

Post by Stephen1966 »

Thanks guys! After chatting with Martin about this (see Whopperplate's link) I drew up a board that uses a couple of trimmers. I left the trimmers in place. There seems no reason to replace them for fixed resistors. This works fine and using precision trimmers I can dial it in to within a couple of millivolts. Nothing conclusive from the biasing - I haven't used the FET much yet, but it's quite easy to go from 14V/7V to 18V/9V for more headroom.

C2 is the 100pF. I could modify the traces a bit there so that it will take either ceramic or mica - why not?
FET 2.2.jpg
Edit: should explain, my FET Level is a 10k CTS pot on the front panel and the FET is connected up via a relay to a footswitch.
You do not have the required permissions to view the files attached to this post.
Stephen
www.primatone.eu
Stephen1966
Posts: 1017
Joined: Sun Nov 03, 2019 1:53 pm
Location: Czech Republic
Contact:

Re: New 183 build

Post by Stephen1966 »

bepone wrote: Sat Sep 24, 2022 6:53 pm
Stephen1966 wrote: Sat Sep 24, 2022 8:28 am
I have a serious question, more a mini-dilemma and I just want to double check this with you. The schematic from jaysg (cca. 2010) only shows the FET circuit in a block diagram. The '100W in the style of #183' from mdroberts1243 outlines the FET and apart from a difference in value of the bias resistor (Rs) this looks identical to the Bluesmater FET.

Bluesmaster FET.jpg

But both of these are different again from the FET in the 124, which I have built and which I can confirm works fine. Although, I did finally reduce the filter cap there from 100uF to 47uF. I'm thinking I can use the same circuit again, only with the 47uF and a substitution of the 100pF X5F ceramic cap for a mica. I make my own PCBs but I guess Martin's boards would work fine there.

Is there any controversy there? Do I have my facts straight?
100pf ceramic ok,
47-100uf no difference
FETs are all different also from the same series, you need to do biasing, with resistor Rs - source resistor.
90% you need to adjust something, so instead of Rs put some trimmer on wires and after adjusting you can put resistor. You can bias hot , middle or cold. Interesting FET circuit with cheap j201 is working very nice, you can make also drive stage biasing it..
With the J201(TO-92) it's the same gate/drain/source connections but without a case connection as in the TO-72. You don't need to change any of the other components in the circuit?

NTE452s here https://www.tme.eu/cz/details/nte452/tr ... ectronics/. About 3x the price of the J201.
Stephen
www.primatone.eu
User avatar
bepone
Posts: 1669
Joined: Mon Mar 09, 2009 4:22 pm
Location: Croatia
Contact:

Re: New 183 build

Post by bepone »

Stephen1966 wrote: Sun Sep 25, 2022 5:15 pm
With the J201(TO-92) it's the same gate/drain/source connections but without a case connection as in the TO-72. You don't need to change any of the other components in the circuit?

NTE452s here https://www.tme.eu/cz/details/nte452/tr ... ectronics/. About 3x the price of the J201.
if you are copying 1:1 183's circuit then need to adjust drain and source resistors.
if you want to try some other great circuit instead what i'm recommending, then you can build this circuit, with 0 bias, adjust supply voltage to be 9V (probably drop resistor from Ub+ line will be cca 220k or so, need to adjust it after powering on)
https://nexp.pt/tpe123/duendejfet.gif
Stephen1966
Posts: 1017
Joined: Sun Nov 03, 2019 1:53 pm
Location: Czech Republic
Contact:

Re: New 183 build

Post by Stephen1966 »

bepone wrote: Mon Sep 26, 2022 8:54 am
Stephen1966 wrote: Sun Sep 25, 2022 5:15 pm
With the J201(TO-92) it's the same gate/drain/source connections but without a case connection as in the TO-72. You don't need to change any of the other components in the circuit?

NTE452s here https://www.tme.eu/cz/details/nte452/tr ... ectronics/. About 3x the price of the J201.
if you are copying 1:1 183's circuit then need to adjust drain and source resistors.
if you want to try some other great circuit instead what i'm recommending, then you can build this circuit, with 0 bias, adjust supply voltage to be 9V (probably drop resistor from Ub+ line will be cca 220k or so, need to adjust it after powering on)
https://nexp.pt/tpe123/duendejfet.gif
The Duende :) Thank you! The J201 has some different parameters to an NTE452 but both FETs are just a handful of parts. Okay, I will give it a go! The boards are easy to access and swap out. It will be in the listening...
Stephen
www.primatone.eu
User avatar
bepone
Posts: 1669
Joined: Mon Mar 09, 2009 4:22 pm
Location: Croatia
Contact:

Re: New 183 build

Post by bepone »

Duende is working until half of the pot like clean boost, and after is beautiful crunch! It is working with 0 bias (note no resistors in source) and like that is genious circuit, because nobody in universe is using JFET in positive (+) bias zone ,maybe 10 people on the Earth in total :lol:
Actually is very linear zone until +0.6V.
User avatar
martin manning
Posts: 14308
Joined: Sun Jul 06, 2008 12:43 am
Location: 39°06' N 84°30' W

Re: New 183 build

Post by martin manning »

Stephen1966 wrote: Sun Sep 25, 2022 5:15 pmNTE452s here https://www.tme.eu/cz/details/nte452/tr ... ectronics/. About 3x the price of the J201.
If you want to do the HAD FET boost, 2N4416A is fine. In EU Mouser has the Pb free TO72 version available for $6.75.
Stephen1966
Posts: 1017
Joined: Sun Nov 03, 2019 1:53 pm
Location: Czech Republic
Contact:

Re: New 183 build

Post by Stephen1966 »

martin manning wrote: Mon Sep 26, 2022 12:04 pm
Stephen1966 wrote: Sun Sep 25, 2022 5:15 pmNTE452s here https://www.tme.eu/cz/details/nte452/tr ... ectronics/. About 3x the price of the J201.
If you want to do the HAD FET boost, 2N4416A is fine. In EU Mouser has the Pb free TO72 version available for $6.75.
Thanks Martin, sure, I've used the 2N4416A in the board I posted. They aren't terribly expensive and they work fine, bepone is correct though, if you ever have to replace them, it's likely they will need to be rebiased. I guess the Pb free version is RoHS compliant then? The board above is with a socket so I can try the NTE452, and swap it out if I want. More for experimental purposes than anything else. I seriously doubt they would ever need to be replaced.
Stephen
www.primatone.eu
cys
Posts: 51
Joined: Thu Oct 29, 2020 5:55 am
Location: Southern California

Re: New 183 build

Post by cys »

I've turned a sonic corner with the 183 I built recently, and it wasn't by changing resistors, caps or transformers in the amp -- it was by tweaking a guitar. I had initially found the 183 overdrive was making a signal that was too busy, kind of a harmonic mess, with the humbucker guitars I have on hand. I have a Les Paul that I've probably swapped eight pickups through getting it to sound right for other amps. One set of pickups was close to being good (BKP Stormy Mondays), so I started magnet swaps with it. The third magnet swap did the trick for another amp... alnico III's. I tried it with the 183, and it's as close as I've gotten to some of the Cream type tones. I'm finally hearing some overdrive tones that captured my interest and drew me to this amp (properties like the OP described in the first post).
Stephen1966
Posts: 1017
Joined: Sun Nov 03, 2019 1:53 pm
Location: Czech Republic
Contact:

Re: New 183 build

Post by Stephen1966 »

cys wrote: Tue Sep 27, 2022 8:33 am I've turned a sonic corner with the 183 I built recently, and it wasn't by changing resistors, caps or transformers in the amp -- it was by tweaking a guitar. I had initially found the 183 overdrive was making a signal that was too busy, kind of a harmonic mess, with the humbucker guitars I have on hand. I have a Les Paul that I've probably swapped eight pickups through getting it to sound right for other amps. One set of pickups was close to being good (BKP Stormy Mondays), so I started magnet swaps with it. The third magnet swap did the trick for another amp... alnico III's. I tried it with the 183, and it's as close as I've gotten to some of the Cream type tones. I'm finally hearing some overdrive tones that captured my interest and drew me to this amp (properties like the OP described in the first post).
Hello Cys - OP here!

You seem like someone who knows their pups. I basically use Seymour Duncan Hot Rails with series and parallel switching. They are all-rounders with a wide sonic palette. However, your experience with all these different kinds of pups and mods tells me that your search for the strange brew of tone could be better directed at the one common factor you describe: the amp. If you read these pages you are likely to come away with the impression that induction is something of a Dark Art. But lead dress, the proximity of components to each other on the board. The interaction between transformers, the chassis and the components internally all produce an EMF signature. Get it wrong and the amp will sound dry and lifeless, get it right and the amp will start to sing. MrD talked about "circuit constants" and this was what, I believe, he was referring to.

Have other people tried playing your amp and come away with the same impressions you found? Resistor and cap types make a difference as well, otherwise why not build an amp using all wirewound resistors? People may disagree about the level of difference these components make, some people hear it, some don't. But everyone agrees at least, that the type of components we use, make some difference. But if you're happy with where you are with it, good-on-ye! However, if you are at a crossroads with your thinking about this "problem", you should feel free to look again at the amp. Changing your approach could make it the sunshine of your love :lol:

Stephen
Stephen
www.primatone.eu
Post Reply