18 watt tmb tremolo build question

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Bieworm
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18 watt tmb tremolo build question

Post by Bieworm »

Josh

What can I expect from your design on that amp...is it more gainy that the classic 18 watt? Is there A fair account of cleanish headroom on tap or is it a crunch-only amp?
I am building the board , but I would like to know if there is some clean to be obtained.
Also, the regular TMB has a MV/gain knob..is it possible to adapt that one on your design?
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Re: 18 watt tmb tremolo build question

Post by JMPGuitars »

I dunno, maybe. ;) The extra gain stage to drive the preamp will likely give it a little more punch, but you're the first person building it, so you'll have to let us know.

Headroom can be adjusted with the B+. Build it first and see how it sounds.
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Re: 18 watt tmb tremolo build question

Post by Bieworm »

JMPGuitars wrote:
Tue 03/03/20 10:23 am
I dunno, maybe. ;) The extra gain stage to drive the preamp will likely give it a little more punch, but you're the first person building it, so you'll have to let us know.

Headroom can be adjusted with the B+. Build it first and see how it sounds.
Well..the board is in progress...
It's pretty crowded btw..the right side isn't finished yet, but on the left it's New York City .
I wonder if it's going to give me trouble. The 8k2 resistors are going to be connected directly to the EL84's. That's the blue wiring..
20200303_201744.jpg
And damn Wima's with their short legs...there is nothing else available. Even the .0042uf caps are out of stock. I guess a .01uf as a substitute will alter things too much huh?
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Re: 18 watt tmb tremolo build question

Post by JMPGuitars »

Bieworm wrote:
Tue 03/03/20 2:23 pm
Well..the board is in progress...
It's pretty crowded btw..the right side isn't finished yet, but on the left it's New York City .
I wonder if it's going to give me trouble. The 8k2 resistors are going to be connected directly to the EL84's. That's the blue wiring..
And damn Wima's with their short legs...there is nothing else available. Even the .0042uf caps are out of stock. I guess a .01uf as a substitute will alter things too much huh?
Yeah, I custom make all my boards, so I can space them out however I like. Those holy boards are cool for small circuits, but they do get crowded fast.

Not all WIMAs have short legs. Pay attention when you order, or google the model number to see. My WIMA caps mostly have long leads, except for some of the smaller/lower voltage ones I have.

I don't know where you're ordering from, but I just checked Mouser and they have many thousands of 4700pF WIMA caps in the 400 to 630 volt range (as well as their other ranges).

Thanks,
Josh
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Re: 18 watt tmb tremolo build question

Post by Bieworm »

I buy mostly at a local electronic components store. Usually they have everything I need, but not now clearly.
I am going to order online. Taking a few days off of building.. the family is starting to complain ;)
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Re: 18 watt tmb tremolo build question

Post by zaphod_phil »

Bieworm wrote:
Tue 03/03/20 2:23 pm
Even the .0042uf caps are out of stock. I guess a .01uf as a substitute will alter things too much huh?
It depends on where it's being used. I've searched through the TMB Tremolo schematic Read and don't see any .0042uf caps :-/
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Re: 18 watt tmb tremolo build question

Post by Bieworm »

zaphod_phil wrote:
Sat 03/07/20 2:10 pm
Bieworm wrote:
Tue 03/03/20 2:23 pm
Even the .0042uf caps are out of stock. I guess a .01uf as a substitute will alter things too much huh?
It depends on where it's being used. I'm searching through the TMB Tremolo schematic Read and don't see any .0042uf caps :-/
Oh yes there are 4... but I seem to have written .0042..should have been .0047!! But I have them now.. the board is ready, except the groundwiring
20200307_212523.jpg
15836128610641068937592724220718.jpg
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Re: 18 watt tmb tremolo build question

Post by JMPGuitars »

For future reference you should do the ground bus wires before putting anything on the board. The grounds buses generate a lot of heat soldering them in, and you don't want that on the components. I'd use heatsinks while soldering it in for your current build.

For me, the process is:
1. Build the board, including the bus wires
2. Solder the wire connections to the board
3. Solder the components to the board

That way the least amount of heat is applied to the components in the process of building the amp.

Thanks,
Josh

PS. I'm looking forward to hearing this when you're done.
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Re: 18 watt tmb tremolo build question

Post by zaphod_phil »

Bieworm wrote:
Sat 03/07/20 3:28 pm
Oh yes there are 4... but I seem to have written .0042..should have been .0047!!
So that's what they are! I thought I must be going crazy :lol:
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Re: 18 watt tmb tremolo build question

Post by Bieworm »

JMPGuitars wrote:
Sat 03/07/20 4:21 pm
For future reference you should do the ground bus wires before putting anything on the board. The grounds buses generate a lot of heat soldering them in, and you don't want that on the components. I'd use heatsinks while soldering it in for your current build.

For me, the process is:
1. Build the board, including the bus wires
2. Solder the wire connections to the board
3. Solder the components to the board

That way the least amount of heat is applied to the components in the process of building the amp.

Thanks,
Josh

PS. I'm looking forward to hearing this when you're done.
Thx for the tips. Will learn from that a lot!
Step by step... becoming an addict. Got the classic 18W to work with all the right voltages yesterday. That was a quest on itself, but I learned a lot along the way.
The TMB tremolo is really itching... it is not going to be long now before it wil run. Already plan to rip the guts out of my newlywed classic an go for the JMP design. You'll get a well deserved mention on a proper place on the amp,Josh!
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Re: 18 watt tmb tremolo build question

Post by pacealot »

Just wanted to crash your thread to say that I just registered here specifically because I'm incredibly interested in this specific circuit, so I'm following your build closely (and anxiously!). Trying to work up both the nerve and the finances to follow suit and build it myself as well.

I did have a question/observation: I noticed that one of those .0047µF caps shown on the layout is listed as .047µF (actually .05µF) in the schematic. It's the one going to ground from the run of three .01µF caps in the tremolo speed section of V1 (the rightmost of the ones on the layout). Curious as to which value is meant to be correct...
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Re: 18 watt tmb tremolo build question

Post by Bieworm »

pacealot wrote:
Sun 03/08/20 3:32 pm
Just wanted to crash your thread to say that I just registered here specifically because I'm incredibly interested in this specific circuit, so I'm following your build closely (and anxiously!). Trying to work up both the nerve and the finances to follow suit and build it myself as well.

I did have a question/observation: I noticed that one of those .0047µF caps shown on the layout is listed as .047µF (actually .05µF) in the schematic. It's the one going to ground from the run of three .01µF caps in the tremolo speed section of V1 (the rightmost of the ones on the layout). Curious as to which value is meant to be correct...
Welcome on 18W !!!
Well the build is in progress.. the board is ready for implanting and the wiring at the PT is finished just now.
Shoot! That is a good question. I put in a .0047, but you're right I think. In the classic tremolo that is a .047 in that spot.
This calls for Josh? Phil? .0047 or .047? Wouldn't the .0047 make it a very slow trem?
Thanks in advance for the bright answers :)
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Re: 18 watt tmb tremolo build question

Post by JMPGuitars »

Whoops. Nice catch with the typo. Please download the corrected layout: files/JMPGuitars_18_Watt_Tremolo_TMB_Layout.pdf

I would correct the cap in your build.

Also, .05 and .047 or .005 and .0047 are respectively effectively the same. I wrote them as .05 in the schematic to match the original for highlighter verification testing, and left them because I was too lazy to change them to the values I use since it makes no difference. ;)

Thanks,
Josh
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Re: 18 watt tmb tremolo build question

Post by Bieworm »

[quote=JMPGuitars post_id=245022 time=1583717518 user_id=2]
Whoops. Nice catch with the typo. Please download the corrected layout: files/JMPGuitars_18_Watt_Tremolo_TMB_Layout.pdf

I would correct the cap in your build.

Also, .05 and .047 or .005 and .0047 are respectively effectively the same. I wrote them as .05 in the schematic to match the original for highlighter verification testing, and left them because I was too lazy to change them to the values I use since it makes no difference. ;)

Thanks,
Josh
[/quote]
I find you far from lazy Josh!
Will change the cap in a few hours, when I come home from work.
Just have to put in the pots for trem int + speed and I can wire the thing up.
Also redid the wiring for the heaters. Now they're even more properly twisted all over.
Is there any harm in tiewrapping all wires at the PT in a few strands to keep things neat and tidy? I already did, but I don't know if there are wires in that area that absolutely need to be separated?
I know that preampwires and heaterwires need to be apart..
Any other stuff I need to know to avoid hum and oscillation?
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Re: 18 watt tmb tremolo build question

Post by Bieworm »

20200309_224052.jpg
Tubes are wired now. Tomorrow the pots
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