Marshall Style 1987 Build, Which Choke?

[Inspector #20]

Seems like a good explanation to me. It was identical on a few different sites.

“A choke is an iron core inductor used in the power supply of a guitar amp as a filtering element. Looking a lot like a transformer a choke only has two leads coming from the housing. They are designed to block AC while passing DC. Their purpose in guitar amp filter supplies is to smooth out the ripple in the rectified DC.”

Wow...i can't quite figure that out!

 

[Inspector #20]

Once you go four input Marshall you'll never go back.

My bandmate has a Germino 4 Hole Lead 55. Great for AC/DC tribute type stuff, but dry beyond that.

I would say the JVM-410C is a far superior live amplifier, IMHO of course...

 

[Cadorman]

Wow...i can't quite figure that out!

It puts the lotion in the basket....

 

[SG John]

Wow...i can't quite figure that out!

The wave forms between AC and DC voltage are both very different. Where it is the purpose of the tubes and other components to convert AC power to DC, it is the choke‘s job to smooth the „ripple“ of the AC sine wave that will still be lurking in the background.

 

[Inspector #20]

The wave forms between AC and DC voltage are both very different. Where it is the purify the tubes and other components to convert AC power to DC, it is the choke‘s job to smooth the „ripple“ of the AC sine wave that will still be lurking in the background.

My lack of understanding in this area keeps me using DSL40C's.

 

[Inspector #20]

Can transformers be built in lightweight versions???

 

[SG John]

My bandmate has a Germino 4 Hole Lead 55. Great for AC/DC tribute type stuff, but dry beyond that.

I would say the JVM-410C is a far superior live amplifier, IMHO of course...

My ‘89 JTM45 reissue is a great amp. Bought it New in ‘89. Over the years many guitar players, live sound engineers, and recording engineers have raved how good that amp sounds. It is also consistent regardless of what speaker I plug into. I was happy to see when they started doing shoot-outs with an early ‘60s JTM45, my reissue, and all the boutique builders. My reissue always won, and sound the most like an early ‘60s amp. The Germino, Mojave, and several others never were able to sound remotely close. They did change the circuit a year or two later, and they didn’t sound the same. Got lucky with mine. I still use that amp as a basis for how good an amp should sound.

 

[Inspector #20]

My ‘89 JTM45 reissue is a great amp. Bought it New in ‘89. Over the years many guitar players, live sound engineers, and recording engineers have raved how good that amp sounds. It is also consistent regardless of what speaker I plug into. I was happy to see when they started doing shoot-outs with an early ‘60s JTM45, my reissue, and all the boutique builders. My reissue always won, and sound the most like an early ‘60s amp. The Germino, Mojave, and several others never were able to sound remotely close. I still use that amp as a basis for how good an amp should sound.

View attachment 47635

I have no doubt of those facts, Man. I used to have a 2203 modded by Tim Caswell and the big Marshall cab shown in your photo. I got tired of needing a Suburban to go to rehearsal. I sold it for 10 times what i paid for it.

I'm looking hard at the Kemper Profiler Board...amp and pedalboard in one unit. Only two cables and zero effects.

 

[ivan H]

Could you explain the function of the choke???

A choke offers low resistance & high impedance. Resistance is to DC what impedance is to AC, in that resistance opposes the flow of DC current, impedance opposes the flow of AC current.
The output tube "plates" (anodes) undergo large current swings which result in voltage swings across the output transformer primary (ohms law). As the HT supply is connected to the OT primary, these voltage swings appear on the HT supply (think of it as AC voltage superimposed on the HT's DC voltage). The choke then let's the DC component flow through it relatively un-opposed, while greatly opposing the flow of the AC component (forcing it to go to ground via the "main" filter capacitor), so the rest of the amp can be supplied nice, clean, ripple free DC.
Hope this is understandable.

Looks very good Cadorman, well done. Glad it's sounding good too. The '68 spec 50 Watter is right up there amongst my favourite Marshalls. Cheers

 

[Inspector #20]

A choke offers low resistance & high impedance. Resistance is to DC what impedance is to AC, in that resistance opposes the flow of DC current, impedance opposes the flow of AC current.
The output tube "plates" (anodes) undergo large current swings which result in voltage swings across the output transformer primary (ohms law). As the HT supply is connected to the OT primary, these voltage swings appear on the HT supply (think of it as AC voltage superimposed on the HT's DC voltage). The choke then let's the DC component flow through it relatively un-opposed, while greatly opposing the flow of the AC component (forcing it to go to ground via the "main" filter capacitor), so the rest of the amp can be supplied nice, clean, ripple free DC.
Hope this is understandable.

Looks very good Cadorman, well done. Glad it's sounding good too. The '68 spec 50 Watter is right up there amongst my favourite Marshalls. Cheers

It is indeed well explained. I'm just out of my league in this area...

 

[SG John]

I have no doubt of those facts, Man. I used to have a 2203 modded by Tim Caswell and the big Marshall cab shown in your photo. I got tired of needing a Suburban to go to rehearsal. I sold it for 10 times what i paid for it.

I'm looking hard at the Kemper Profiler Board...amp and pedalboard in one unit. Only two cables and zero effects.

Nita Strauss uses the Boss version of that.

 

[Inspector #20]

Nita Strauss uses the Boss version of that.

She has a video of herself playing in a hotel room, and the tone is simply fabulous.

 

[Mitch Pearrow SJMP]

My lack of understanding in this area keeps me using DSL40C's.

Micky on the MF installed a choke on his Dsl40c and he had pics of the installation, but no clips, it is in the giant Dsl40c information thread.

Mitch

 

[Cadorman]

I removed the resistors and installed chokes in both of my 900's. There is a difference, but not like you would notice it in a stadium with 20,000 people.

 

[syscokid]

She has a video of herself playing in a hotel room, and the tone is simply fabulous.

I would love to play with Nita in a hotel room...

 

[Cadorman]

The 50 watt has taken the throne seat on the stack. I’m really liking this amp. It sounds very open and natural. Maybe what you would call organic.

 

[Cadorman]

Here's an audio clip. SG, both pickups, neck volume about 3/4 of bridge. A wee amount of reverb from my HOF and a slight midrange bump in my MXR 10 band. Amp volume 1 on about 1 and volume 2 about 3/4 of 1. All other controls at 12 o'clock.

 

[Cadorman]

Same exact thing with a little RAT. Distortion set at 10 o'clock and filter just shy of 3 o'clock. This amp takes pedals really well.

 

[syscokid]

View attachment 47669
















Same exact thing with a little RAT. Distortion set at 10 o'clock and filter just shy of 3 o'clock. This amp takes pedals really well.

Gotta love those RAT pedals... I smell some Blackberry Smoke in your play'n.... :dood:

 

[Cadorman]

Gotta love those RAT pedals... I smell some Blackberry Smoke in your play'n.... :dood:

I think I saw them once on Jules Holland.