Solid State Guitar Amp Forum | DIY Guitar Amplifiers

Solid State Amplifiers => Preamps and Effects => Topic started by: Katoda on January 03, 2016, 11:08:52 AM

Title: EVH 5153 preamp with LND150
Post by: Katoda on January 03, 2016, 11:08:52 AM
Just to see how it would have turned up, I attempted to recreate the preamp from the ultra-high-gain EVH 5153 (the Fender version) with the base of research being KMGs fantastic JCM800 preamp with LND150 mosfets, implementing the diode grid current limitation and therefore closely emulating the 12ax7 tubes. I ran out of space pretty quickly, because I was using two perfboards superglued together in a recycled enclosure from a 'true' tube Pittbull preamp project. It looks ugly as ****, but it cost me about 10€ (except the LND150, I had everything at home and/or at hands reach) and it sounds awesome. Having never played the original amp I cannot claim it sounds the same, but from what I heard on YT, its pretty close.

Pics:
http://i63.tinypic.com/e13jtt.jpg
http://i66.tinypic.com/ofop4p.jpg

Some sound samples - Lasse Lammerts DI tracks reamped  through the thingy, with some impulses (Peavey 4x12, i think - or recto):
https://soundcloud.com/user-119965807/evh-5153-preamp
https://soundcloud.com/user-119965807/evh-5150


Title: Re: EVH 5153 preamp with LND150
Post by: phatt on January 05, 2016, 03:03:50 AM
Hi Katoda, Welcome to the forum :tu:
Hey thanks for sharing, Yes KMG has done some very impressive work. :dbtu:
Sounds big but I assume you only built the preamp?
Also I'm a bit lost as to impulses, How does that happen exactly?

I'd like to hear a recording of the circuit coming from a Real Guitar> Amp> speaker and miked up recording.
Phil.
Title: Re: EVH 5153 preamp with LND150
Post by: Katoda on January 05, 2016, 04:14:06 AM
Hello, thank you  :)
Yes, I only built the preamp, which is going to be played through the FX loop of my Fryette Deliverance project. I don't currently have the amp at home, but as soon as I get it I will post some clips. I am also anxious to try it with a real tube power amp, so far I have only played it through a small tda2030 based thingy.
The impulses are basically recorded speaker frequency response and behaviour, so a sort of fancy eq. It doesnt sound quite as good as a miced up cab, but at the time it was (and sort of still is) the only option. I have to ask a friend to borrow his mic again.  ::).  But kind of the reason I didnt play any actual riffs myself is that I've heard these DI tracks in many gear demos and I thought it might be a good comparison with the real thing. But I will put up something for sure, this little preamp is my favourite new toy :)
Also, perhaps it is worth the mention that this thing has waaay more distortion than I need, so I have already changed the 1M gain pot for a 100k one. Way better, now I can get it in the zone where it cleans up nicely with the guitar volume pot.
Title: Re: EVH 5153 preamp with LND150
Post by: phatt on January 06, 2016, 05:09:53 AM
Thanks for the explanation of recording process, sounds complicated xP
I'm actually more interested in how it sounds through your tda2030 thingy (or similar) as that won't colour the sonic result as much giving a more realistic impression.
Yes I also don't need total distortion so cleanup with guitar volume is much preferred.
Keep us posted,,
Phil.
Title: Re: EVH 5153 preamp with LND150
Post by: Katoda on January 11, 2016, 12:09:36 PM
Hi,
I didn't have a proper mic so I just turned the volume waaay down until the phone mic wasn't clipping and recorded a sample of the cleanup with the guitar volume knob.
 https://soundcloud.com/user-119965807/evh-5150-preamp-phone-recording-of-guitar-volume-cleanup
Gain was on 11 o'clock, on the recording I gradually increase the guitar volume.

EDIT: Listening to it again, the gain was set kinda high, metal territory...
Title: Re: EVH 5153 preamp with LND150
Post by: phatt on January 13, 2016, 05:41:46 AM
That is quite impressive, :dbtu:
Yes very dynamic and tone alters as the volume increases,, hum interesting indeed. 8|

Which preamp section of the amp did you build?
What voltage does it run on.?
Better still any chance you have a schematic?

Please :)

Phil.
Title: Re: EVH 5153 preamp with LND150
Post by: Katoda on January 13, 2016, 07:46:43 AM
Thank you :)
I followed the lead channel of 5153 schematic (fender), with a basic gain stage like the one KMG came up with, using Bav99 and Bat54s diodes, from this post:
http://www.ssguitar.com/index.php?topic=2039.0
R3 was 180ohm, except on the third stage, where there is an unbypassed 39kohm source resistor, there its 270ohm. In the original schematic, the cathode resistors are mostly 1.8k with 1uF bypass and 2.2k, here the source resistors are mostly 2k2 with 1uF bypass and 2k7. Plate resistors are the same. The resistor before the 1uF capacitor is 680ohm.
For the power supply i have a 15V AC input, from which one path leads to a rectifier and 7812 regulator to get -12V for biasing the mosfets, and the other goes to an ugly 230-12V Ac transformer on top of the enclosure, which gives out about 340V.Filter caps are 2 680uF/200V in series, each in parallel with a 270kohm resistor.
The gain pot in 100kohm with 4.7nF treble bleed cap, as opposed to a 1M with 1nF.
And instead of the cathode follower on the 5153 version, the tone stack is plate-driven, as in 5150.

Sorry, I don't have a schematic, but this is pretty much it :)

Title: Re: EVH 5153 preamp with LND150
Post by: phatt on January 14, 2016, 12:05:09 AM
Thanks for the explanation. :tu:
Phil.
Title: Re: EVH 5153 preamp with LND150
Post by: stratitis on March 23, 2020, 04:41:08 PM
Hi,
I didn't have a proper mic so I just turned the volume waaay down until the phone mic wasn't clipping and recorded a sample of the cleanup with the guitar volume knob.
 https://soundcloud.com/user-119965807/evh-5150-preamp-phone-recording-of-guitar-volume-cleanup
Gain was on 11 o'clock, on the recording I gradually increase the guitar volume.

EDIT: Listening to it again, the gain was set kinda high, metal territory...
That sounds great in my ears!
What final amp did you use? That TDA2030 or your Fryette?
Title: Re: EVH 5153 preamp with LND150
Post by: Katoda on March 25, 2020, 04:55:18 PM
Hi,
I didn't have a proper mic so I just turned the volume waaay down until the phone mic wasn't clipping and recorded a sample of the cleanup with the guitar volume knob.
 https://soundcloud.com/user-119965807/evh-5150-preamp-phone-recording-of-guitar-volume-cleanup
Gain was on 11 o'clock, on the recording I gradually increase the guitar volume.

EDIT: Listening to it again, the gain was set kinda high, metal territory...
That sounds great in my ears!
What final amp did you use? That TDA2030 or your Fryette?

Thank you!
I used a TDA2030 power amp, I think I had the tube amp at the band rehersal place.
Title: Re: EVH 5153 preamp with LND150
Post by: stratitis on March 26, 2020, 04:09:10 AM
I used a TDA2030 power amp, I think I had the tube amp at the band rehersal place.
That's great, so I could use one of my cheap practice amps as final amp for testing.
To supply about +300V I could use 2 mains transformers back to back (for example: 230VAC -> 30VAC -> 30VAC -> 230VAC -> rectifier -> ~320VDC)
Could you post your schematics, please?
Title: Re: EVH 5153 preamp with LND150
Post by: Katoda on March 26, 2020, 06:53:57 AM
That's great, so I could use one of my cheap practice amps as final amp for testing.
To supply about +300V I could use 2 mains transformers back to back (for example: 230VAC -> 30VAC -> 30VAC -> 230VAC -> rectifier -> ~320VDC)
Could you post your schematics, please?
Two back to back transformers will be fine at such low currents, that's also how I got the high voltage to the preamp.
Unfortunately I don't have the schematic, I followed the official tube amp schematic while adjusting it for the LND150 circuit directly on a piece of perforated pcb. I described the changes a couple of posts back. It has been a while since I last tinkered with that preamp, but if you really need the schematic, I can whip something up in KiCAD. It might not be *exactly* the preamp that was demoed, since I don't remember every detail, but it will probably sound closer to the real 5150/5153 (if you want a schematic, do tell which 5150 version are you after).
Title: Re: EVH 5153 preamp with LND150
Post by: stratitis on March 26, 2020, 07:41:00 AM
Unfortunately I could not find schematics of the 5150 III (=5153 ?).
All I found is the attached ones:
Title: Re: EVH 5153 preamp with LND150
Post by: stratitis on March 26, 2020, 07:46:15 AM
Do you know if they sound different?
I thought they are nearly the same, maybe I'm wrong.
How did you "adjust" the single stages?
Title: Re: EVH 5153 preamp with LND150
Post by: stratitis on March 26, 2020, 08:02:45 AM
Sorry, still found 5150 III schematics (Fender).  ;)
Which one did you refer to?
Did you build all 3 channels or just one?
Title: Re: EVH 5153 preamp with LND150
Post by: Katoda on March 26, 2020, 08:27:20 AM
Do you know if they sound different?
I thought they are nearly the same, maybe I'm wrong.
How did you "adjust" the single stages?

Yep, the 5150 III is made by Fender, not Peavey, the schematics are still widely available via google search. :) It does sound a bit different, a bit more high end bite, but the underlying feel of the 5150 is pretty much the same.

I only built the high gain channel, the cleans on the original 5150 are not that impressive and the other two channels of the 5153 would require a lot more gain stages.

The adjusting was done by comparing the two circuits, LND150 and the original 12ax7 stage. The plate or drain resistor is the same, so is the grid resistor and the coupling capacitor. The diode biasing circuit is exactly the same as proposed in KMGs article, but the bias circuit (with the PNP BJT transistor) is adjustable with a trimmer. What would be the cathode resistor and bypass capacitor in the tube stage are changed slightly by comparing the KMGs Marshall preamp circuit and the original JCM800 schematic. I used what i had, so it was the next closest E24 value. Instead of a 1.8k resistor I put in a 2.2k one and so on. The bypass caps are not really that important here, as the 5150 by itself already cuts bass below 800Hz in the first stage. I think I left them at 1uF.
Also, I put in a 500k gain pot with a resistor to decrease the maximum gain. It has a lot of it.

Most of the circuit in the preamp I recorded is 5153, but I didn't have any room on the perfboard left for a source follower tone stack, so I just made it plate driven, as in the original 5150. That probably cost me some highs, as the impedance is higher, but it wasn't that bad.
Title: Re: EVH 5153 preamp with LND150
Post by: stratitis on March 27, 2020, 02:23:30 PM
Thanks for your detailed reply.
Still a lot of work to do.  I try to extract a simplified schematic (one channel) as you did, to build a prototype for testing.