Mesa Subway Blues Power Tubes Daughter Board Rebuild

[sluckey]

sluckey.... I don't know that you're helping the situation here...

~Phil

I wasn't trying to be helpful. I believe my description is very accurate. People like this guy discourage a lot of normally helpful people from ever offering help to newbies. I did learn something though... I didn't realize we had so many color choices for fonts.

OK, I'll be quiet.

[Pyramid Head]

I'm sorry about my lengthy posts: I try to be as thorough as possible and I have difficulties with synthesis.

It saddens me to see that one bad reaction on my part, followed by a sincere apology, wasn't enough (what would be then?) to make up for my bad.

I really hate to reveal this about me, as I have seen people treat me differently, but in this case I think that the benefits far outweigh the cons...

I am an Asperger, a high level autistic person.
That's why I might express myself in a sometimes peculiar way. Also why I have trouble with making shorter posts when I'm very tired at 5 am: synthesis requires a big effort on my part. Also why I initially missed the context, "misread the air".

One thing I am NOT is a self-absorbed, arrogant POS who smells his own farts and thinks highly of himself.

I can apologize for what I could have done differently, what is under my control. But in the end, I know that some people won't like me and however much I try to please everyone, I don't have to apologize for being different, however much I wish it could be so...

This Thread, my arrival on this forum is an absolute disaster! I'm tired of talking about myself & I hope that this last bit of info will be enough to clarify things and clean the air. Yes, I am a new "poster" on this forum, but I 've been following it for a long time and I love the community.

If there's anything else I can do to help resolve the tensions, please tell me. I have edited the offending post, as promised.
All I wish is for us to start over.

Thanks for your comprehension.
That was quite shorter, was it?

[sluckey]

Much shorter. This topic has been viewed 190 times. Sometimes you just can't put the genie back in the bottle. Probably something to be learned here for all.

[pompeiisneaks]

You're fine. I think you've gotten some good information. You could get a few terminal strips and connect them to the power tubes and be fine I'm sure.

~Phil

[Pyramid Head]

Hello everyone!

Thanks. And indeed, I did get many useful tips.

Before closing the door on the thread, I'd have a few final questions. Oh damn! I didn't see the time!

I'll ask part of my questions & I'll come back later today.

~> I was wondering if it makes any tangible difference if someone:
A) uses a Turret to connect one lead of a Resistor to then connect the other lead directly to a tube socket pin.
B) Uses 2 Turrets to which both leads of the Resistor are connected, before then using a wire to connect one Turret to the Socket Pin.

~> I haven't yet reached the chapters talking about Lead Dressing. I've been reading online, and I'm finding lots of contradictory opinions...

In the following question, could you please enlighten me with what to do & avoid? Like if it's important to keep some wires at a 90° angle from others? Sorry, I'm rushing it.

Here. I have been looking for inspiration and have found some pictures of neat layouts (to my eyes).

~> Could you please let me know what you think of this way of wiring the EL84 Sockets?

- Since I only have 2x Sockets to wire, we can forget about the pair on the right.
- My OT Wires will be coming from the right contrary to these pictures, but won't make any difference.

- My Heater Wires are coming from the left, and there's not much play so I'll have to connect them horizontally directly to the left socket. That leaves the daisy chain routing...

Do you think it would be best to just send the twisted pair of wires directly to the right socket to keep the wite length as short as possible or would it be a good idea to bring the wires down to the chassis' edge and do like in the picture?

Does it matter? If so, why?
And 18 or 20AWG?

~> I like the 2 Strips approach a lot, with bus wire & eyelets (could use turrets too). Do you see any problems with this approach?

~> Where do you source your eyelets?

~> Any other thoughts?










~> I was wondering if you guys know & could recommend a software/app that people use to easily draw their amp's layout?

Thanks so much again!

Christian

[martin manning]

~> I was wondering if it makes any tangible difference if someone:
A) uses a Turret to connect one lead of a Resistor to then connect the other lead directly to a tube socket pin.
B) Uses 2 Turrets to which both leads of the Resistor are connected, before then using a wire to connect one Turret to the Socket Pin.

Resistors connecting to pins 2 and 9 (control grid and screen grid) are best located as close to the socket pins as possible to prevent oscillation. I would just get a couple of three-lug terminal strips and arrange the components as shown below.

Question about this amp: I see it has a record-out circuit which looks interesting. Does it work well? Looks like there is a 1H inductor, can you confirm and check to see if there is a part number on it?

[pompeiisneaks]

One turret is fine, so long as it is physically close to the socket. If it's on a board a ways away from it, it's better to use two turrets/eyelets and then run a wire between that and the socket.

As for lead dress, there's a ton to learn and it's not easy to explain quickly. Generally keep high voltage wires away from the signal wires, like the B+ rails and the PT/OT and their currents. Keep the the farthest from the first gain stages as they are the most sensitive. That first picture is heater wiring, and is one of the better ways to do it, but I and many others have found that unless you're building an extremely high gain amp, heaters introduce very little noise. Often, in those cases where it will be very high gain, they convert the heaters to to DC instead of AC as that's much cleaner. You can also just elevate the heaters higher than 0V as their base reference to reduce noise. In this case, for power tubes, it's not really a big deal as the tube has such strong signal it doesn't allow much leak of noise into the signal path. (again the first stages are most sensitive) Fender, for all the tubes used to do a pretty minimalist winding of the heater wires loosely above the socket with no big concern for potential bleed. As for the rest of the layout, it looks nice, that's using some Garolite board almost like a turret strip. It gets the job done of isolating the electronic components and looks nice and tidy.

As for wire, the only wire in an amp that needs to be 18GA is the heater wires for the power tubes as they run at pretty heavy current... The rest of the amp can be 22GA very easily. That's what I use on all my builds.

As far as sourcing them, that depends on where you are in the world. In the US I like to buy them from Antique Electronic Supply (AES) tubesandmore.com

In Europe there are many forum members that can tell you their favorite sources of components.

As far as software apps, there are several that are great. I and sluckey like visio. He created a ton of components you can download from his site at sluckeyamps.com
If you don't have visio and/or don't want to pay for it, there's another often used one called DIY Layout Creator: https://bancika.github.io/diy-layout-creator/

Et de plus il y a plusieurs francophones ici, je connais du moins 3... 2 qui sont en France et moi ici aux etats unis. Je n'ai pas la facilite a faire les accents puisque je n'ai jamais utilize un ordinateur avec le clavier configure a azerty et je me trompe de trop

~Phil

[ChopSauce]

In Europe ...

... oh, yes: https://www.tube-town.net/ttstore/eyele ... 0-pcs.html

[thetragichero]

definitely use terminal strips over turrets/eyelets for this. for two el84 heaters i wouldn't do larger than 20awg, and you could likely get away with 22awg (i can tell you from experience that using 18awg wire on 9 pin socket pins is NOT a fun time). if your amp uses global negative feedback, make sure to mark which ot primary leads goes to which socket as oscillation will occur if these are reversed