The Real James Jamerson Amp

[beans-on-toast]

I've heard stories that the early Beatle recordings that were recorded at EMI studios in London,later renamed Abby Road Studios, were very much looked down upon by American recording engineers because of this, no bottom end to the sound, not full sounding. Much fuller sound on the re-mastered CD versions IMHO Jim

The Beatles have said that they wanted to have more bottom on their records and that it was down to how the disk cutter was used at EMI. They had strict rules.

In the link above (post 216) Bob olhsson from Motown talks about a visit he had to Abbey Road Studios and touched on what they did to achieve a better master.

When CD's came out, the EMI remasters weren't constrained in the way that they were with vinyl. As a result, there is more bottom present. As technology improves, they remaster and improve thesound even more. The Beatle tracks on the Love soundtrack have a wonderful clarity as well as highs and lows (bandwidth).

 

[Jeff Scott]

Hallowed ground.

 

[markjazzbassist]

i've done more research on this. Mike McClean said he copied from circuits around that time to make the "Motown preamp" as well as their console and 8 track reel to reel. It's documented by Bob Olhsson that they had Langevin Preamps (Tube), Altec 1567a Tube Mixer, Scully 280 Preamp, Ampex MX-10 Tube Mixer and the Motown Homemade Preamps.

The only commercial preamp around the early to mid 60's that used 12ax7 tubes was the Bill Putnam 610 (we now know this as the Universal Audio 610). So i will casually infer that possibly the Motown Pre was "loosely based" on the Putnam 610 except with UTC transformers and other possible mods by McClean.

thoughts?

 

[beans-on-toast]

i've done more research on this. Mike McClean said he copied from circuits around that time to make the "Motown preamp" as well as their console and 8 track reel to reel. It's documented by Bob Olhsson that they had Langevin Preamps (Tube), Altec 1567a Tube Mixer, Scully 280 Preamp, Ampex MX-10 Tube Mixer and the Motown Homemade Preamps.

The only commercial preamp around the early to mid 60's that used 12ax7 tubes was the Bill Putnam 610 (we now know this as the Universal Audio 610). So i will casually infer that possibly the Motown Pre was "loosely based" on the Putnam 610 except with UTC transformers and other possible mods by McClean.

thoughts?

It was an interesting time. Back then, studios were mostly owned by record labels and they often designed some of their own equipment or modified commercial products to suit their needs. Records made at one studio used some equipment that only that studio had. There was no shortage of engineers working in studios that knew how to design and get the most out of tube circuits so they built equipment. The UA610 was a desirable preamp. Below is an image of Neil Young's UA console based on the 610.

For instance, the EMI RS124 compressors that were modified Altec units are highly sought after. Bob Olhsson talks about visiting EMI ([Invalid or Expired Link Removed] so the community did share some ideas.

The Ampeg 351 tape amplifier is one example of a design that used a 12AX7 in the front end. McIntosh preamps such as the 175 and 275 had 12AX7's in their front ends. Other studio gear such as the Teletronix LA-2A has a 12AX7 pre in the front end and the Pultec EQP-1A had 12AX7 and 12AU7's. So I guess that there were studio equipment design ideas that they could have borrowed from.

 

[markjazzbassist]

It was an interesting time. Back then, studios were mostly owned by record labels and they often designed some of their own equipment or modified commercial products to suit their needs. Records made at one studio used some equipment that only that studio had. There was no shortage of engineers working in studios that knew how to design and get the most out of tube circuits so they built equipment. The UA610 was a desirable preamp. Below is an image of Neil Young's UA console based on the 610.

For instance, the EMI RS124 compressors that were modified Altec units are highly sought after. Bob Olhsson talks about visiting EMI ([Invalid or Expired Link Removed] so the community did share some ideas.

The Ampeg 351 tape amplifier is one example of a design that used a 12AX7 in the front end. McIntosh preamps such as the 175 and 275 had 12AX7's in their front ends. Other studio gear such as the Teletronix LA-2A has a 12AX7 pre in the front end and the Pultec EQP-1A had 12AX7 and 12AU7's. So I guess that there were studio equipment design ideas that they could have borrowed from.


View attachment 677169

great call i forgot about the 351, pultec and teletronix. they had a pultec as well so they could have used that design, interesting. 351 is a strong possibility as well, they did have the mx-10 and based their reel off ampex as well. great call!

 

[beans-on-toast]

great call i forgot about the 351, pultec and teletronix. they had a pultec as well so they could have used that design, interesting. 351 is a strong possibility as well, they did have the mx-10 and based their reel off ampex as well. great call!

Their monitor amp in the studio (below where they plugged in) was a McIntosh as I recall.

 

[markjazzbassist]

Their monitor amp in the studio (below where they plugged in) was a McIntosh as I recall.

yes but it was a power amp only so no preamp circuit to copy there.

 

[beans-on-toast]

yes but it was a power amp only so no preamp circuit to copy there.

It could have been based on a McIntosh pre-amp design that used 12AX7's. They were feeding a 30W (maybe an MC-30?) McIntosh power amp - see the quote in the first link.

In case you haven't seen these: Soulful Detroit Forum
lots of info on Bob's site: Invalid Link Removed

 

[Eirthug]

A reply to all.

Very interesting story.

However I think we should not forget the musician's style of attack and their ears.
I can take any bass, any amp, and produce numerous variations in tone just by changing how I play; not to mention how much my state of mind or mindlessness affect my sound; oh, and let's not forget "the room". I have an Ampeg Portaflex, which has tone controls that actually do something, with a wide range of tones to be had.

Being a tubehead, I think that cool pre-amp/monitor is the best. Like many engineers of that period, they had to make a lot of their own gear. 4-track recording was new then; Srgt. Peppers was recorded on a 4-track!

Thanks Dan for sharing that awesome photo of that beautiful piece of vintage/priceless tube gear!

Eirthug

 

[beans-on-toast]

A reply to all.

Very interesting story.

However I think we should not forget the musician's style of attack and their ears.
I can take any bass, any amp, and produce numerous variations in tone just by changing how I play; not to mention how much my state of mind or mindlessness affect my sound; oh, and let's not forget "the room". I have an Ampeg Portaflex, which has tone controls that actually do something, with a wide range of tones to be had.

Being a tubehead, I think that cool pre-amp/monitor is the best. Like many engineers of that period, they had to make a lot of their own gear. 4-track recording was new then; Srgt. Peppers was recorded on a 4-track!

Thanks Dan for sharing that awesome photo of that beautiful piece of vintage/priceless tube gear!

Eirthug

Welcome.

No question that Mr. Jamerson had a lot of awe inspiring tone and talent in his hands.

Feel free to drop by the Portaflex thread: Official Ampeg Portaflex Club.

Also, there is the TB Portaflex Wiki with a lot of related information: Ampeg Portaflex Wiki | TalkBass.com.

 

[BassLand]

It is also important to note that this preamp was the first stage in the signal chain. The preamp fed into the McIntosh power amp for monitoring in the studio while recording. It wasn't just this signal that got printed to tape for the final master.

Reports also indicate that a Fairchild limiter and a Pultec EQ were part of Jamerson's sound. Then there was the pre-amp in the mixing board. If you look at pictures of the studio, there were several pieces of outboard gear in the racks.

The pre-amp is a piece of the story but the total picture is not clear. It is amazing that after all these years, there isn't a definitive description that everyone can agree on, of what was used when and where in the signal chain for such an important piece of history.

Then there is the tape saturation aspect of what would be the "sound" of Jamerson's bass. At Motown, they bounced back and forth mixing existing tracks down to a mono mix on a second machine and adding tracks to be mixed down to still other generations. Before the final mix (especially in the early days).

 

[beans-on-toast]

Whatever they did, it was magic. As you said, Jamerson played hard, that sent a strong signal into the preamp which could add saturation. Some people acheive this with a clean overdrive pedal.

James Jamerson Jr recently passed away. He made this tribute to his dad.

 

[DanielPampuri]

I think the piece of gear that played the biggest part on his sound was made by his parents. Just saying

 

[hopeless_opus]

I don't know if this has already been posted, but anyone interested in Jamerson's sound or Acme Audio products should definitely read this from the designer/inventor of the Motown DI, aka, the Wolfbox. It gives some insight into how Jamerson was recorded, and calls into question the integrity of Acme's products.

Link: Link Removed

It's an interesting story for sure, here is the closing excerpt:

""The "Wolfbox" cannot, and will not, give you the tone and amplitude consistency of James Jamerson, Sr. or Jr. Nor will it give you Bob Babbit's transient control. It will not give you the precision of Chris Lopes. Nor will it will not give you the the chops of Eddie Willis or the crying wah-wah of Dennis Coffey. No, you won't have the bite of Paul Lamb. All of that is PURE HYPE. What it will give you however is clean, unsaturated, realistic reproduction of the input instrument with the best of 60s and 70s era technology. The rest is up to you and your skills.

So it is therefore in the spirit of the Detroit audio business as it was when I came up, and with the hope that the tradition of the studio owner/engineer/craftsman will continue, you will find the link below to the .pdf file schematic of the “Wolfbox” for your own non-commercial use. Build it. Package it as you wish. Play around with different input transformers, new (without “Moly,” I pray.) and vintage. Learn how to make reciprocity analysis of the differences. You will discover that your ears are variable and far from an accurate and consistent method for analysis. You'll gain much knowledge and insight from the experience.

Above all, have fun! Make GOOD music and thank God for the skills he has given you. And if the mood strikes, send me pictures of your packaging. I'm eager to see (and maybe even hear) your results!

Thank you greatly for your time.

Ed Wolfrum




NOTE: The “Wolfbox” is essentially in the public domain, other than the new attenuation network that I designed and was completed at Audio Graphic Services. That part is protected but will now be released under the Creative Commons license for non-commercial use.""

 

[Woodstockz]

Whatever they did, it was magic. As you said, Jamerson played hard, that sent a strong signal into the preamp which could add saturation. Some people acheive this with a clean overdrive pedal.

James Jamerson Jr recently passed away. He made this tribute to his dad.

Since about 1964, when me and my friends sang "My Girl", I have always been a huge Motown fan.

RIP James and Son.

 

[DustyTru]

Dan thank you very much for this information ...I genuinely appreciate the specific true and actual details you bring to light & have waited a long time to hear them as I have not come across them elsewhere and understand their significance in the grand scheme of righteous sound Legacy ...all these other grumpy holes trying to detract from what you're saying and then talk ' what I really meant ' garb can go kick rocks

 

[MarkA]

I don't know if this has already been posted, but anyone interested in Jamerson's sound or Acme Audio products should definitely read this from the designer/inventor of the Motown DI, aka, the Wolfbox. It gives some insight into how Jamerson was recorded, and calls into question the integrity of Acme's products.

Link: Link Removed

It's an interesting story for sure, here is the closing excerpt:

""The "Wolfbox" cannot, and will not, give you the tone and amplitude consistency of James Jamerson, Sr. or Jr. Nor will it give you Bob Babbit's transient control. It will not give you the precision of Chris Lopes. Nor will it will not give you the the chops of Eddie Willis or the crying wah-wah of Dennis Coffey. No, you won't have the bite of Paul Lamb. All of that is PURE HYPE. What it will give you however is clean, unsaturated, realistic reproduction of the input instrument with the best of 60s and 70s era technology. The rest is up to you and your skills.

So it is therefore in the spirit of the Detroit audio business as it was when I came up, and with the hope that the tradition of the studio owner/engineer/craftsman will continue, you will find the link below to the .pdf file schematic of the “Wolfbox” for your own non-commercial use. Build it. Package it as you wish. Play around with different input transformers, new (without “Moly,” I pray.) and vintage. Learn how to make reciprocity analysis of the differences. You will discover that your ears are variable and far from an accurate and consistent method for analysis. You'll gain much knowledge and insight from the experience.

Above all, have fun! Make GOOD music and thank God for the skills he has given you. And if the mood strikes, send me pictures of your packaging. I'm eager to see (and maybe even hear) your results!

Thank you greatly for your time.

Ed Wolfrum




NOTE: The “Wolfbox” is essentially in the public domain, other than the new attenuation network that I designed and was completed at Audio Graphic Services. That part is protected but will now be released under the Creative Commons license for non-commercial use.""

Just wanted to say thanks for posting that. I read through the whole thing. I don't have a lot of the context that some of you guys have -- either in tech background or in familiarity, directly or indirectly, with the recording scene, characters, and practices of the 60s and 70s -- but I am interested in the music and the sounds and this was an interesting bit of background and character insight.

 

[markjazzbassist]

i was wondering when someone would finally get into motown to draw up the circuit in the custom Motown Tube Preamp used by the bassists and guitarists. Looks like Acme Audio has done it.

Acme Audio MTP66 2018 ((Presale of Final Production Units)) Motown Tube DI & Preamp

I definately won't be paying that, but look forward to hearing about them.

FWIW looks like a hammond and cinemag transformer on there, not sure about the one without a cover on it.

 

[beans-on-toast]

i was wondering when someone would finally get into motown to draw up the circuit in the custom Motown Tube Preamp used by the bassists and guitarists. Looks like Acme Audio has done it.

Acme Audio MTP66 2018 ((Presale of Final Production Units)) Motown Tube DI & Preamp

I definately won't be paying that, but look forward to hearing about them.

FWIW looks like a hammond and cinemag transformer on there, not sure about the one without a cover on it.

It would be interesting to see a gut shot.

They seem to have merged a mic pre with a DI on the input.

 

[Johnny Vance]

So this morning I decided to get to the bottom of what Jamerson used at Studio A to get that distinctive, fat, dirty tone. I've heard 2 different stories over the years: that he used his Ampeg B-15 in studio, or that he plugged directly into the mixing board. This is the most common story. But of course this got me thinking - exactly what brand board did he plug into?

Well I just came across this gem of a thread that explains it all in detail: Soulful Detroit Forum

There are posts by Bob Babbitt and engineers that actually worked at Studio A, including Mike McLean who built the funky 5-channel tube amplifier/DI that the guitars and bass were plugged into. The speaker in the amp was not mic'd. It was only there to allow the musicians to hear what they played. Everything on tape was the direct signal from that device.

View attachment 1907814

"We decided that five such preamp channels (five guitars) would be sufficient to meet all practical needs.

In addition, a monitor mixer was required to mix together the five preamp outputs so that the resulting modulation could be fed to a power amplifier and speaker so that the musicians could hear themselves.

The original monitor system that was in use at Motown when I arrived in 1961 consisted of two Altec Lansing type 605-A "Duplex" coaxial speakers which were a fifteen inch low frequency unit with a separate compression driver with a 4 by 2 multicell horn mounted in the center. These speakers were capable of very high sound levels without being damaged.

We had replaced these speakers with other units that were supposed to be an improvement, and we had the two of them sitting in the store room. The musician's guitar monitor seemed like an ideal application for one of these speakers. Further we had a lovely McIntosh type MC-30 mono 30 Watt power amplifier sitting in the store room.

The combination of this amplifier and speaker promised to provide very reliable and appropriate monitoring for the musician. This proved to be true in practice. We built an infinite baffle (sealed box) cabinet for the 605-A, which would take the place of all the old clunker, humming, Fender amplifiers that the musicians used to drag in. Space was at a premium in the old Hitsville studio, and elimination of all those Fender amps and the microphones, with stands, to pick up the sound, was a big advantage.

At first, the tendency was to think in terms of installing the five preamps in the control room, and possibly having them equipped with variable gain controls to that the recording engineer could adjust for correct line output level. I didn't like this because gain pots tend to get noisy, and most important of all, it is difficult to maintain the maximum dynamic range in a preamp which must accommodate a wide range of gain. I liked the idea of a fixed gain preamp that was designed for maximum performance at that gain.

The thought occurred to me that it would be hip to make the setting of the preamp output level the responsibility of the musician. If the preamp gain was sufficient to allow a moderate setting loss on the volume control on the musical instrument, then it would be ideal to simply have the musician set this instrument volume control to provide the correct line level at the preamp output. All that was needed was a VU meter in the studio so that the musician would know when the level was correct. The preamp was designed with fixed gain.

The second step was for the musician to adjust the mixer pot on the little five-channel monitor mixer so that his volume level was comfortable over the Altec 605-A speaker.

We mounted five beautiful 3.5 inch rectangular Triplett VU meters, five rotary monitor mixer pots, and five quarter inch input jacks for the guitar cables, on a seven inch high rack panel, and built the five vacuum-tube preamps on a Bud aluminum chassis mounted directly behind the panel.

The preamps were designed to provide first class professional performance specifications, in accordance with the discussion above. In practice, the recording engineer could forget all about the guitars (except, of course, for mixing them.) He automatically had a perfect line level to patch into his console, because the musician had adjusted the level right at his guitar, using his VU meter. The musicians loved the sound of that McIntosh/Altec combination, and could set the speaker volume to suit their requirements very easily. The entire system was as reliable as the tide, and worked beautifully. Everybody loved it.

I feel that it worked out very well to assign the responsibility for the level control to the musician. As far as I know, we never had any problems with improper levels. I got the feeling that it made the musician feel good to be responsible for this function.

Considering the horrors that could happen when a musician turned down his instrument volume control, while at the same time the recording engineer was fooling around jacking up the gain on a variable gain preamp: It seems to me that this design approach was a minor "stroke of genius." (If you don't mind me saying so.)

If only everything I did at Motown had made as much sense as this did!"

- Mike McLean

Absolutely. As is most times the case, we put way too much emphasis on gear. Instead of playing. Getting better. SRV, Jamerson, all the greats, sound like themselves using crappy gear or the best.