When did Marshall change their 4x12 wiring to parallel-series?

fearhk213

Well-known member
I’m curious when Marshall changed their 4x12 wiring from series-parallel (speaker to jack) to parallel-series? Was it in 1990 to accommodate the mono/stereo jack on the JCM900 cabs or was it sometime before that?
 
It’s basically how you get a 16 Ohm load out of four 16 Ohm speakers on a mono jack so I imagine they’ve used it for a very long time.

***edit** I totally misread your post 🤦‍♂️ so my answer is …I don’t know..
 
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I don't know either. Recently been trying series parallel and parallel series in several cabs with different speakers.
Interesting how different the sound and feel is of both types of wiring.
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Not my words but this is exactly how it breaks down:

"Series wiring- mid/upper mid and high end emphasis generally, smoother high freqs generally due to damped top end highs in the 5 to 6k range, less fizz. Additional tonal changes are slightly spongier attack and altered OD character, more complex and timbrally rich with more overtones ala the mid and top end emphasis.

Parallel wiring- low end and lower mid emphasis with more top end high sparkle or fizz, depending on the speaker and rig that can make the high end raspy or harsh to some. Low end is emphasized due to increased damping between 2 12" speakers in parallel, generallly tighter and more thump. Parallel- for heavier OD tones, more modern tone as in todays tuned down uber bottom tones with raspy highs, tighter thump think Tool etc

for cleans, more headroom and usable travel on the guitar pot, more high end sparkle in the 5 to 6k range since the parallel spkr coil config means the extreme high end is not attenuated through each coil in series, more hifi sounding in general with bottom and very top end emphasis

Series- more vintage flavored with less bottom more mids and top end but not as extended into the Presence range of 5 to 6k more suitable for shred where you spend much time on strings 1, 2 and 3 etc. speed picking etc. Too much presence and its Razer Blades to the ears. Less headroom overall meaning less clean and its dependent on the rig of course"

I prefer parallel/series with V30 type speakers as that wiring helps extended the bandwidth of the narrow V30 EQ spectrum. Now that I'm back to vintage G12-80s I'm preferring series/parallel as those speakers have a wider more balanced frequency response.
 
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Not my words but this is exactly how it breaks down:

"Series wiring- mid/upper mid and high end emphasis generally, smoother high freqs generally due to damped top end highs in the 5 to 6k range, less fizz. Additional tonal changes are slightly spongier attack and altered OD character, more complex and timbrally rich with more overtones ala the mid and top end emphasis.

Parallel wiring- low end and lower mid emphasis with more top end high sparkle or fizz, depending on the speaker and rig that can make the high end raspy or harsh to some. Low end is emphasized due to increased damping between 2 12" speakers in parallel, generallly tighter and more thump. Parallel- for heavier OD tones, more modern tone as in todays tuned down uber bottom tones with raspy highs, tighter thump think Tool etc

for cleans, more headroom and usable travel on the guitar pot, more high end sparkle in the 5 to 6k range since the parallel spkr coil config means the extreme high end is not attenuated through each coil in series, more hifi sounding in general with bottom and very top end emphasis

Series- more vintage flavored with less bottom more mids and top end but not as extended into the Presence range of 5 to 6k more suitable for shred where you spend much time on strings 1, 2 and 3 etc. speed picking etc. Too much presence and its Razer Blades to the ears. Less headroom overall meaning less clean and its dependent on the rig of course"

I prefer parallel/series with V30 type speakers as that wiring helps extended the bandwidth of the narrow V30 EQ spectrum. Now that I'm back to vintage G12-80s I'm preferring series/parallel as those speakers have a wider more balanced frequency response.
You were the one who got me to try parallel-series lol. That was definitely one of those eye opening gear experiments lol. What you quoted there is how I've found the differences as well. And like you, I've also found I can prefer one way over the other depending on the scenario.

What actually prompted the question in my initial post is I got to wondering if Marshall was still using the series parallel wiring when they first started using the G12 Vintage. That may have had some influence on the direction things went when it was designed. Being that speaker is tighter with bigger lows and a bit more "smiley" face in eq than the standard V30's, it has me wondering if the G12 Vintage would be a good candidate to try the vintage style series parallel.
 
I’m curious when Marshall changed their 4x12 wiring from series-parallel (speaker to jack) to parallel-series? Was it in 1990 to accommodate the mono/stereo jack on the JCM900 cabs or was it sometime before that?
Mesa ships their 4x12’s that way too. I just re-wired mine; need to add the switch. Aiken wiring with the switch ought to be a factory option imho.
 
It is exactly like what thegame posted.

I had a cab that was too bright after I rewired it the balance was so much better. I can definitely see where both types are useful.
 
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What cab? Did it start p/s like Mesa/Marshall/VHT?
Actually I did more. It was Sunday. I picked up two empty Peavey 4x12 cabs. A M and MS from the 80's. The ones that came with G12K-85.

I had two G12H-75 creamback in a 80's Marshall cab with two Vintage 30. I pulled the speakers and put them in the straight Peavey 4x12. Wired it parallel series.

The original Marshall Vintage 30 went back in the Marshall cab.

Currently have seven 4x12. Wired both ways. A 2x12 with EVM12L. Two Orange 1x12 with Vintage 30. I have been switching out speakers in the cabs a lot the last year. Trying different combinations and wiring. I have a Ampeg System Switcher. So I can switch 8 cabs in real time. It's been interesting.
 
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Well, what have you found?!
I'm still in the process. I plan on buys 4 more speakers to fill the slant Peavey cab.
Pair of Redback. Not sure of the other pair yet.

I tend to like parallel series.

Individual speakers can be very different.

I tend to like straight cabs. But like both for the differences.

The Marshall cabs are brighter and more resonant. Mesa Rectifier cabs are darker and less resonant. The old Peavey cabs sit between these two. Probably my favorite cabs.

The Fryette Deliverance P50E 4x12 because it has a adjusted resonance is a very focused sound.

We are getting pretty far off topic. I don't believe the OP original question was answered yet.
 
I'm still in the process. I plan on buys 4 more speakers to fill the slant Peavey cab.
Pair of Redback. Not sure of the other pair yet.

I tend to like parallel series.

Individual speakers can be very different.

I tend to like straight cabs. But like both for the differences.

The Marshall cabs are brighter and more resonant. Mesa Rectifier cabs are darker and less resonant. The old Peavey cabs sit between these two. Probably my favorite cabs.

The Fryette Deliverance P50E 4x12 because it has a adjusted resonance is a very focused sound.

We are getting pretty far off topic. I don't believe the OP original question was answered yet.
Which way are digging with the Marshall voiced V30’s?
 
Which way are digging with the Marshall voiced V30’s?
I actually only played on it a few minutes with a THD Univalve to see if it was working. It's the typical stereo switching cab. I run it 16 ohm. Not sure but believe it is parallel series.
 
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I actually only played on it a few minutes with a THD Univalve to see if it was working. It's the typical stereo switching cab. I run it 16 ohm. Not sure but believe it is series parallel ?
Ok if it’s wired up the same way they come stock, it would actually be parallel series. With 16 ohm speakers that wiring allows you to get two 8 ohms pairs when running stereo. If it’s series parallel, you would end up with two 32 ohm pairs when running stereo.

Edit: to add to it, Engl wires their Pro cab in series parallel, but with 8 ohm speakers. That way they end up two 16 ohm pairs.
 
Ok if it’s wired up the same way they come stock, it would actually be parallel series. With 16 ohm speakers that wiring allows you to get two 8 ohms pairs when running stereo. If it’s series parallel, you would end up with two 32 ohm pairs when running stereo.

Edit: to add to it, Engl wires their Pro cab in series parallel, but with 8 ohm speakers. That way they end up two 16 ohm pairs.
So the 4 ohm setting is parallel parallel ?

That makes sense. I was changing my post before I saw yours. Lack of sleep.
 
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