Complete Build VLOG For My Latest 102

[talbany]

Would I achieve the same results doing this method on a soldered board or would be best to remove the caps for this testing

Unfortunately, you have to pull em
At the very least I would make sure
V1b coupler and V2a & V2b(.01/.0047) are foil to plate

These are the most critical.

Good Luck!

Tony

[Bombacaototal]

Would I achieve the same results doing this method on a soldered board or would be best to remove the caps for this testing

Unfortunately, you have to pull em
At the very least I would make sure
V1b coupler and V2a & V2b(.01/.0047) are foil to plate

These are the most critical.

Good Luck!

Tony

Many thanks for the reply Tony, that will be fun on the hotel hog I am working on, 2 channels, reverb and tremolo

All or nothing for me...getting ready to rip it apart

[norburybrook]

Tony, do you think that the new generation of orange drop caps which are clearly manufactured differently due to their diminished size would have any baring on a comparison? i.e are they made 'better' now so the orientation 'might' not be as imperative? or conversely made worse now so more important.


as we're on this, why do a lot of manufacturers of film/foil caps not mark the outer foil if it's important? and why not use a higher quality cap like WIMA for example that will have better specs all round?



here's some fun reading for you all

http://www.laventure.net/tourist/caps.htm

check out the cap prices $269 for a 300v 1uF



MC


p.s. Bombacaotal I've used the squeezing method to do my foil orientations on the odd occasion I've bothered. I don't have a scope but you can hear it, so it's not a difficult thing to do....if you can hear well of course

[martin manning]

Marcus, following your link and a link therein: http://www.laventure.net/tourist/Capaci ... tation.pdf
This guy says the the outside foil markings on Sprague caps were never accurate since the manufacturing process was not capable of finding it. I think that could be the case for caps that have markings printed on after dipping, as long as some other indicator like different lead lengths wasn’t provided.

WIMA caps sound good according to reports I cave seen. No reason not to use them. Why don’t manufacturers mark the outside foil? The answer to that is obvious: it’s not important to anybody they care about!

[Bombacaototal]

Thanks Marcus, I don’t have a scope as well but just bought a small portable one called Seeed 109990013 DSO Nano v3 Digital Oscilloscope which was not ultra expensive as everything else I’ve seen and will hopefully do the job!

[norburybrook]

Marcus, following your link and a link therein: http://www.laventure.net/tourist/Capaci ... tation.pdf
This guy says the the outside foil markings on Sprague caps were never accurate since the manufacturing process was not capable of finding it. I think that could be the case for caps that have markings printed on after dipping, as long as some other indicator like different lead lengths wasn’t provided.

WIMA caps sound good according to reports I cave seen. No reason not to use them. Why don’t manufacturers mark the outside foil? The answer to that is obvious: it’s not important to anybody they care about!

LOL good point.

If I get time I'm going to record my second gen amp as it is now, no foil orientations, new dales. I'm also going to profile it extensively with my Kemper. I'm then going to remove the caps and mark the outside foils and put them back correctly and also Charlie has got me some NOS dales I'm going to put it. I'll then repeat the recording and profiling so I'll have a before and after for posterity.

I have a web shop selling kemper profiles so I would be profiling that amp soon anyway.

Mechanically how could I safely wire up the resistors so I could quickly AB them? I'd need a switch for everyone wouldn't I, or could I do them in pairs?




M

[martin manning]

This will be a great service to the community, so thanks to both you and Charlie in advance! Be sure to track the cap orientation as currently installed so you know which ones have been swapped. You may have been lucky in your random installation ;^)

On the plate loads, you can do them in pairs by connecting the center lugs on a DPDT to the plate eyelets on the board, and then each pair of resistors in a V, open end of the V on each outer pair of lugs on the switch. Then join the pointy ends of both V’s and connect that to the supply eyelet on the board (same as the resistor V on the standard layout normally goes to). If you use solid wire for the connections to the plate eyelets I think this assembly would be self-supporting. A mini toggle would handle the voltage.

[norburybrook]

This will be a great service to the community, so thanks to both you and Charlie in advance! Be sure to track the cap orientation as currently installed so you know which ones have been swapped. You may have been lucky in your random installation ;^)

On the plate loads, you can do them in pairs by connecting the center lugs on a DPDT to the plate eyelets on the board, and then each pair of resistors in a V, open end of the V on each outer pair of lugs on the switch. Then join the pointy ends of both V’s and connect that to the supply eyelet on the board (same as the resistor V on the standard layout normally goes to). If you use solid wire for the connections to the plate eyelets I think this assembly would be self-supporting. A mini toggle would handle the voltage.

actually that's a good point about noting where they are now

the bit's for my tweedled dee are arriving any day so that may take priority however.

I shall start a new thread when I do the tests. it will be a while before charlie's resistors get to me I think.


M

[talbany]

Tony, do you think that the new generation of orange drop caps which are clearly manufactured differently due to their diminished size would have any baring on a comparison?

I doubt it since the foil end of the cap will still act as a shield

as we're on this, why do a lot of manufacturers of film/foil caps not mark the outer foil if it's important? and why not use a higher quality cap like WIMA for example that will have better specs all round?

Probably adds to the cost of the cap. It also depends on the circuit it is going in!. Since we are building tone generators we are concerned with a low noise floor and most of these caps probably go in other things As far as the Wima or other high-quality caps if you like the sound of a Wima cap or any other cap knock yourself out. Us Dumble pirates generally stick to the Dumble sauce (including resistors)and go with what the big guy uses because we like the sound of his amps. BTW Iv'e run into quite a few caps that are incorrectly marked foil end

Years ago when I first started building amps we tried just about every one out there including the expensive oil fills and Q's. most of them made for a dead sounding amp. Quality does not always yield favorable results in a guitar amp.been there

If I get time I'm going to record my second gen amp as it is now, no foil orientations, new dales. I'm also going to profile it extensively with my Kemper. I'm then going to remove the caps and mark the outside foils and put them back correctly and also Charlie has got me some NOS dales I'm going to put it. I'll then repeat the recording and profiling so I'll have a before and after for posterity.

Just as a for-warning here. Many people here have tried to capture the sonic differences in resistor types and post their recordings!. Some are successful some not so much. In order to get the full 3D picture of the Dales you really need to be in the room playing the amp. Marcus I am still interested in hearing your opinion after the swap.BTW! a few things to listen for with the Dales. Top end clearity and an open sounding (BIG sounding) midrange. On the OD side, the highs are smooth and compressed. The more you drive the OD the more 2nd order you get (vs the new ones that adds 3rd order) Pinch harmonics are effortless..
Good Luck

Tony

[norburybrook]

Tony,

thanks. Yes a guitar amp is an interesting beast from a technical point of view as a lot of times it's the imperfections that make it pleasing to us so it's a balancing act I suppose between technical 'perfection' and pleasing to the ear.


Also I realise that ceratin elements wont be as noticable if you're not driving the amp hard. For example i think the main filtering doesn't really have much baring unless the amp is dimed. i could be wrong here but i've experimented with the main filter caps, doubling them, halving them in value and haven't been able discern any diference. perhaps if i used the amps dimed i might, but that's not how i use them. Same may be true for the outerfoil/resistors, perhaps having the amp dimed will make the difference noticable. i need to take this into consideration when doing the 'tests'

I've been thinking about how to keep the playing consistent to take that out of the equation. I'm going to use a looper but that will take the guitar in the room interaction with the amp out of the equation which as you say may have sonic benefits. it's a tricky one.


regarding capturing, well i have some great mic's here. I'll stick my 1960's U67 on it, that's a beautiful revealing mic worth about $12,000 now and either a sm57 or a nice ribbon. I can guarantee they will capture any nuance Having the amps captured by the kemper profiling procedure will be interesting too for future reference.



I'm hoping the combined result of swapping all the plate resistors AND orienting the caps properly will have some audible result. I think perhaps each individual swap will be imperceptable but overall it would be great to hear a difference of any kind.

I'm keen to learn about this stuff but I'm also wary of dissapearing down a rabbit hole ending in listening to different wire colours.....promise me you'll shoot me before I get there


M

[Bombacaototal]

Looking forward to your tests Marcus. I am receiving the scope today and will do all the foil markings.

The proper way to connect the outside foil is to the low impedance side of the circuit, which, in the case of coupling caps, will normally be the plate of the previous stage. If it is a bypass cap to ground, connect the outside foil to the grounded side.

So the outside foil of the .01uF cap accross the Low Filter (SSS amps) should be towards the 12K to ground and the outside foil of the cap accross the bass pot on a skyliner stack would be on the 10K to ground side, correct?

Now a quick question:
Where should the outside foil of the .001uF just before the high filter be? Towards the coupling cap of V1b or towards the 820K of the high filter?

[norburybrook]

does this help?

DumbleOverdrivespecialOuterFoil-2.jpg

M

[talbany]

Same may be true for the outerfoil/resistors, perhaps having the amp dimed will make the difference noticable. i need to take this into consideration when doing the 'tests'

Marcus look at it this way

Attaching the outer foil acts as a shield. (Like turning your cap into a shielded cable)
What does this do?..It will make the amplifier much less susceptible to outside noise, including hum, interference from what is called EMFR (Electro-magnetic field radiation) and tendency towards oscillations or frequency-response peaks and dips due to unwanted feedback from nearby signals within or outside the amplifier, which can affect the tone of the amplifier (and is the reason why some people claim the amp sounds different if the caps are oriented in the opposite way - if there is no accidental coupling, there will be no tonal difference, but there will still be a noise benefit gained from orienting the caps the correct way).
So What Benefits?
Although you might not notice it now where the amp is sitting, you may have to put the amp in an environment where EMFR is present. Having the extra protection of shielding the caps will help prevent any stray field radiation from getting into your signal path and then wonder.Why does my amp sound different tonight. Sounded great yesterday, when you stuck it right next to a neon or fluorescent lighting or an old house with crappy wiring and anywhere near a rack of dimmer packs or even stack it on another amp that is on. I can give you a list

Some people can feel the difference between different size caps in the preamp (even down low) others not at all

BTW. I don't consider changing 4 plate resistors a Rabbit hole. Starting your own amp company is another story.. It's a Joke!


I hope this helps!

Tony

[Bombacaototal]

Indeed helps Marcus, although the SSS filter question I still need to get my head around where the foil would be

[norburybrook]

Tony,

that does help indeed and your points about protecting against dirty power is one I hadn't thought about and is reason enough that I will orientate my foils correctly from now on just for that alone so thankyou.

Anyone who starts and can sustain an amp making business has my full and utter respect, seriosly, it's almost as mad an idea as becoming a professional musician!



regarding swapping resistors ...it's a slippery slope to the bottom of that rabbit hole!!!







M