Maybe You Have A Juicy Question?

[RealMarkDeneen]

BlueBerry Extreme Schematic - a General schematic.

Notes: I can't recover the far left of the schematic which shows the input jacks. Don't know what happened but it was lost years ago. This again, should serve as a general guide for the design.

[RealMarkDeneen]

GENERAL INFORMATION ABOUT THE JMA DOCS

 

There are now a few people using these docs, and there will be more, I'm sure. I have to provide some context about the docs.

 

As a literal "one man band" I did everything on my own - no help of any kind. No contractors, part timers, helpers - nada. So, unfortunately what suffered was "documentation". In the beginning it was all paper and pencil. Then I tried various software solutions, but none were really suitable for schematics. I ended up using Adobe Illustrator because I already had learned it for other things. It's not a good solution. For Bills of Materials I used an old AppleWorks program no longer made, so trying to recover that info is tough, but I am making some progress.

 

Worse yet, I did not formalize every schematic of every  revision I made. So, for BBX there are probably 15 revisions in circulation and for Peach it might be 10. The schematics I am posting are "as of that date" schematics and don't necessary jive with the unit you have 100%. But the TOPOLOGY is all there.

 

My guess is that a good technician with tube experience will be able to follow the topology and interpret the minor differences in the various revisions. Maybe a 240K resistor got changed to 220K and so on.

 

The PCB layouts are a whole other problem. I used a proprietary service called PCB123. I think I have most of the original files from VERSION 1 of their software. But I have no large format printer. They will send give out links to their version 1 software though to anyone asking for it. Then, using that, a person could open one of my PCB files and either look at it, or possibly print it out. I have no idea how far people want to go, but I mention it as a possibility.

 

The manuals are pretty useless, but I have those PDFs.

 

Sooooooo, I am willing to provide everything I can, but the quality of the info is sort of "average". It's not spot on. And, there are many different revisions of product out there, so I don't want anyone to expect that I can document their specific unit - because I just can't. I can get close. I can get you in the ball park. My bad, but that's what it is.

 

As far as I know, the only parts that are UNOBTAINIUM are the PCB mount RCA jacks, and the color graphic panels.  The LM350 regulator isn't made anymore (I don't think), but you can find them on Ebay. They rarely failed, thank goodness.

 

My intent is to make a DOCS PACKAGE zip file for each of the products. It will be a hodge podge of what I have for each. Some will be richer than others.

[RealMarkDeneen]

Original BlueBerry Schematic -- General Schematic of the original BlueBerry

[BNR_1]

Thank you Mark for posting what you are able to recover with regards to your schematic and other information.  It helps for many of the JM customers like me.  Regards.

[Marvel]

Although I'vd had zero issues for my Merlin, I eagerly await docs/shematic, even pcb layout if and when possible.

 

All of your designs have been great. I did have a BB for awhile, and while nice, I passed it on to someone else. The Merlin serves my needs.

 

Bruce

[RealMarkDeneen]

17 minutes ago, Marvel said:

Although I'vd had zero issues for my Merlin, I eagerly await docs/shematic, even pcb layout if and when possible.

 

All of your designs have been great. I did have a BB for awhile, and while nice, I passed it on to someone else. The Merlin serves my needs.

 

Bruce

 

Thus far, I haven't located a Merlin schematic. If I have to I think I can recreate it from memory. It's the simplest of all the preamps. But, I'm still rumaging through backup disks.

Mark

[captainbeefheart]

Well this is officially bizarre. I must have worked on one of your preamps in the past as I have a schematic called "Tercel". I have no idea where I got it from.

[RealMarkDeneen]

21 hours ago, captainbeefheart said:

Nice work Mark.  I completely understand the "one man show" where precise documentation is mostly in my head and lots of stuff on paper during the design gets lost. Well for me at least. Worst part was my work computer failed before I did a backup and lost a lot of work for boards and schematics that were on that one drive only.

 

RIAA EQ is  1kHz your at +7db, low frequency boost 20Hz +27db and high frequency cut 20kHz -13db.  Looks good to me. This equates to +20db at 20Hz 0db at 1kHz and -20db at 20kHz. Accurate RIAA EQ is an important design constraint and I've seen plenty not very accurate. I was messing around going between active and passive EQ circuits and was leaning towards preferring active EQ vs passive. I still really enjoy the sound of the circuit posted in the old RCA handbooks using a 7025. I prefer it over many other designs so far. Have you heard that circuit Mark? Thoughts?

 

 

 

Hi,

 Thanks for the comments. As for one man band I really stretched the idea to the limits. Of the 20 skills i really needed, I really only had 3. The rest I had to play by ear. 
 

As for the circuit you mentioned I "probably" heard it between 1974 and 2010, but I'm not sure. Over the years i scratched up dozens of phono circuits and of course we all had the Big Red Radiotron book... so probably.  In my Paragon Audio and ADC days we used active eq, but when I began to fool around for Juicy circuits i got hooked on eliminating feedback. If I recall the BBX eq was within 1/2dB or so. I fell in love with the simplicity of the thing. 
 

Like most designers I wish I had done 10 or 20 things differently, but.... that's life!

[captainbeefheart]

3 minutes ago, RealMarkDeneen said:

Of the 20 skills i really needed, I really only had 3. The rest I had to play by ear. 

 

Well you did a great job and should be very proud of yourself. We will never improve ourselves if we don't jump outside our comfort zone, right now I'm trying to get better at the chassis and woodworking aspect of building. I really want to nail down dovetail joints and built a little welding machine to do tack welds for chassis making. People don't understand how much work it entails designing from the ground up the circuits, layout, chassis,.......everything. It takes a company on average 1-2 years to make a prototype and I only have my spare time to do the work. Lately had two completely different builds, they couldn't be further apart in topology and chassis design. Soon they will be done and I can relax and kick the feet up. I don't do this for profit, I only have people pay for the parts as I enjoy the hobby.

 

8 minutes ago, RealMarkDeneen said:

As for the circuit you mentioned I "probably" heard it between 1974 and 2010, but I'm not sure. Over the years i scratched up dozens of phono circuits and of course we all had the Big Red Radiotron book... so probably.  In my Paragon Audio and ADC days we used active eq, but when I began to fool around for Juicy circuits i got hooked on eliminating feedback. If I recall the BBX eq was within 1/2dB or so. I fell in love with the simplicity of the thing.

 

I'm sure you have heard the RCA circuit, it's extremely popular or at least was. Last year I made an EF86 based phono circuit with frequency selective feedback for the EQ and it sounded much better than I anticipated. I have done active in the past, not just with tubes either, I made an active EQ circuit with the LT1358 that I originally purchased a bunch for  I to V DAC conversion but ended up trying them for phono duty and wow, it was the best sounding opamp based circuit I have heard and was blown away with the performance. But at the end of the day I'm a tube guy, the circuit was built for someone else that didn't want tubes but to be honest I could live with the opamp stage if I couldn't go tube.

 

Most of it is probably due to novelty, the ear tends to like new things so I don't trust my judgement all that much in the short term but you can tell if you have a contender when it gets the toes tapping right away.

 

24 minutes ago, RealMarkDeneen said:

Like most designers I wish I had done 10 or 20 things differently, but.... that's life!

 

Ain't that the truth!!!

[RealMarkDeneen]

JuicyMusic Merlin Schematic -

 

@Marvel

 

This is the schematic for the Merlin with 6H30 tube. It should be very close to any Merlin out there.

[RealMarkDeneen]

Tercel Phono Preamp Schematic - -

[RealMarkDeneen]

1 hour ago, captainbeefheart said:

We will never improve ourselves if we don't jump outside our comfort zone

 

Absolutely true. In my exprience, bringing any "idea" to life will almost always require stepping out on uncertain ground, taking chances, and what I like to say is "betting on yourself."  If you won't bet on you, it's hard to expect others to. 

 

 

[RealMarkDeneen]

JMA CDROM?

 

Now, that I am deep into the backup files, and putting up schematics and what not, maybe the smartest move is to create a "JuicyMusic CDROM" with ALL the stuff for ALL the products? Manuals, schematics, BOMs, etc.

 

Seems like that would be a no-brainer. One and done, kind of thing.

[the real Duke Spinner]

A smart person would pay, 

Say, $30

To ensure it was easy to maintain his Product locally

Dont give it away Mark.

.I can see a Customer receiving a Schemo for his purchase

 but not the whole enchilada

 

 

 

 

 

 

 

 

[RealMarkDeneen]

17 minutes ago, the real Duke Spinner said:

A smart person would pay, 

Say, $30

To ensure it was easy to maintain his Product locally

Dont give it away Mark.

.I can see a Customer receiving a Schemo for his purchase

 but not the whole enchilada

 

 

 

 

 

 

 

 

 

Well, I think people put up with a lot of my mistakes and reliability issues, so I'm happy to give it away. I don't think it's anything more than a few pennies at this point. I probably should have done it when I retired.

 

But, I appreciate your generous comment!

 

 

[Marvel]

3 hours ago, RealMarkDeneen said:

This is the schematic for the Merlin with 6H30 tube. It should be very close to any Merlin out there.

 

Thank you, Mark. Mine uses the original 6dj8, but Craig, sent me the changes from that to the 6H30 tube.

 

Would it be a worthy change/upgrade? Current 6dj8 is quiet and sounds great (using the Duke for amplification).

[RealMarkDeneen]

1 hour ago, Marvel said:

 

Thank you, Mark. Mine uses the original 6dj8, but Craig, sent me the changes from that to the 6H30 tube.

 

Would it be a worthy change/upgrade? Current 6dj8 is quiet and sounds great (using the Duke for amplification).

 

Hi Bruce,

Hard to say. I thought the 6H30 was better sounding for my ears, and they were easier to obtain quiet ones than the 6DJ8. It's a pretty easy upgrade. I can post the original schematic too. I found that one also.

 

These days, I find any discussion about "sound quality" to be like discussing fine wines. I have no way to relate my tastes to anyone else. So, the answer is..........."maybe"..

 

[Marvel]

The original would be nice to have if it's no trouble.

[Travis In Austin]

On 10/21/2022 at 1:55 PM, captainbeefheart said:

There really shouldn't be a need for a schematic to make repairs. For very complex circuits on multi-layer PCB boards a schematic can certainly help speed the process up but it's not necessary.

 

Post internal pictures of the amp with description of the issue and I don't mind helping people fix their stuff. I am limited to what I can do physically until my next Dr. appointment so I've been just doing some soldering to Tim's amp and computer based work for the day job.

 

Is your name Mark? He, and others, have requested the schematic from the designer/manufactures, and he is willing to post it here. Take this repair hints and tips to some other thread, and quit crapping in this one. 

[Travis In Austin]

On 10/21/2022 at 1:37 PM, RealMarkDeneen said:

I am back from vacation today Friday the 21st. But on Monday I'll be getting surgery and be out for at least a few days.

 

I'll get some info to Rich today about the power supply. I'll get a few docs ready to mail this weekend, but it will be a little later before I can then address more issues.

Mark

God's speed Mark.