Passinwind

16 hours ago, Killed_by_Death said:

I doubt many of you would attend a Mister Mister concert

That's a safe bet in my case.😎

2 hours ago, ubit said:

Classic cars used to be just cars.

Yep, and all this stuff is just Oldies now. Self included! 😎

2 hours ago, Killed_by_Death said:

 

snapshot of the results so far:

I think I may have hit "definitely" by mistake rather than "definitely not."

16 hours ago, Killed_by_Death said:

 

There's no doubting that Deep Purple influenced some future Heavy Metal bands, but is this particular song Heavy Metal?

 

It was Acid Rock at time of conception, at least to everyone around my social scene. 

18 hours ago, JapanAxe said:

Yep, just a matter of working through it until I find the issue(s). I've done this enough times not to be worried about it. I could always add a silicon rectifier as an option but tbh I don't really think it will be an issue.

Looking good there! It's a pretty simple circuit, shouldn't take too long to scope things out.

We are finally getting a short break from the oppressive heat here (112F one day last week and over 100 for several days in a row) and I'm hoping to finally finish my new one up in the next few days. But of course our wonky Italian espresso machine chose last week as a good time to die, and the last round of replacement parts showed up in my mailbox this morning. Priorities...😎

On 15/06/2021 at 07:31, Passinwind said:

Another day, another janky filter preamp. This one is testing the cheap Tayda C taper dual pots, which so far are "working" but seemingly limiting my preferred tuning options a bit. But in any case the board will go on free share at OSHpark very soon and I also have done a more DIY friendly layout with all through-hole caps that will likely take a month or two to vet thoroughly.

And here the new one with through-hole caps is, tested and working right off the bat as designed and modeled:

At this point I have five working boards to sort through in order to decide on the open source release spec, but this latest one looks to be the likely front runner. The Tayda pots have turned out to work fine so this needn't be a terribly expensive DIY build.

On 18/06/2021 at 07:44, EBS_freak said:

Sorry - yeah, it's a 9v feed on the EBS are requires a 3 core cable into your bass.

IIRC even EBS have called that phantom power at some point, no worries.

My current daily driver bass actually has a 4 pin XLR output and could use +/- 15V external power if I needed it to. Right now I still just have a 9V battery in the breakout box and plan to do a quasi Ric-O thing as soon as my DIY tube amp finally gets finished.

7 minutes ago, EBS_freak said:

Because the current from typical phantom power units won't be enough.

EBS use it from their amps so you can power a pedal. There's nothing stopping you from using a similar mechanism for powering your bass if you have a proper power source. I have such a unit for sending power to my LEDs through the jack on one of my basses.

In the case of EBS that's not actually phantom power in the classic sense,  just outboard power on a dedicated conductor. It works fine in my experience, but it still has the same potential issue with switch-on transients blowing stuff up.

2 hours ago, Killed_by_Death said:

 

Tear out all the active components & go 100% Passive!

 

Yep, an unamplified upright bass is clearly what the OP wants and needs.😎

As @itu advised, a soft start feature is going to be a really good idea in any case.

Another day, another janky filter preamp. This one is testing the cheap Tayda C taper dual pots, which so far are "working" but seemingly limiting my preferred tuning options a bit. But in any case the board will go on free share at OSHpark very soon and I also have done a more DIY friendly layout with all through-hole caps that will likely take a month or two to vet thoroughly.

10 minutes ago, Trueno said:

A few times a decade sounds about right.

Yep, and that's my running total for four basses and one guitar. I prefer food grade pure orange oil (it's killer in brownies too), but those with plastic bits in the line of fire may not want to go that route.

40 minutes ago, Jean-Luc Pickguard said:

What is your experience of fingerboard oil?

I use it in one form or another a few times a decade as a cleaner, whether I need to or not.

On 19/05/2021 at 08:14, Passinwind said:

Still keeping pretty busy, this week I revisited my variable resonance low pass filter design and worked out the glitches:

 

 

I've now ported the design to all SMD format and plan to add it to my open source onboard preamp collection, so anyone who wants to and can deal with SMDs can build their own.

 

And here the new one is, somehow only four days from ordering the PCBs to having a working unit on my test bench:

7 hours ago, itu said:

Ahem, I think this is one interesting PCB... any chance to get a board or at least the data of it, please?

There’s a very long thread on Talkbass with prior art, frequency response graphs,  a schematic link, board share info and bill of materials, and many many tangents: https://www.talkbass.com/threads/the-passinwind-open-source-preamp.1259692/ .
 

At the moment I only have the original Bass/Mid/LPF  three band design on offer as a board share,  but the standalone filter ones should be coming online in the next month or so. I’ll probably start with the SMD version and then look at doing a through hole one eventually too. This is all an open source non-commercial labor of love BTW.

Still keeping pretty busy, this week I revisited my variable resonance low pass filter design and worked out the glitches:

I've now ported the design to all SMD format and plan to add it to my open source onboard preamp collection, so anyone who wants to and can deal with SMDs can build their own.

On 01/05/2021 at 14:23, JapanAxe said:

I probably won't get the transformers for another week as they are being built to order. In the meantime I have been considering my options as regards the heater filaments.

The Ceriatone layout follows the Heritage schematic in having the heater centre tap connected to ground. I would normally do this, or in the absence of a centre tap on the PT I create a virtual CT using 100R resistors between each side of the 6.3V AC supply and ground. Both the 1964 and 1968 schematic show a 100R Hum Balance ('humdinger') pot across the 6.3V, with the wiper (marked K) connected to the cathodes of the output valves, which will be at about 36V above ground at idle. As I understand it, elevated filament voltages are intended to distance the heaters from any noise in the circuit ground, and the pot allows any residual noise on the 6.3V lines to be cancelled out. With proper grounding there shouldn't be any noise, but I think I will compare connecting the heater CT to the cathodes or to ground to see which produces the lower noise floor. If neither approach is satisfactory, I can consider adding a hum balance pot.

If anyone has personal experience of heater noise in the B15 circuit, please do share!

 

I pretty much always just use DC heaters for preamp level circuits these days. It's been a long time since I owned my B-15, but I dont remember it being nearly as quiet as the stuff I've built myself over the last decade or so. That amp was always a bit of a problem child though, unfortunately.

It's very cool seeing a  hand drawn layout, I've been CAD-only for several years now. 😉

5 hours ago, Killed_by_Death said:

I sometimes think truly pitch-perfect people must have a difficult time enjoying Music if there's any pitch issues. If I don't know my timing is off or I'm out of tune, all the merrier.

 

The ones I've known and played with all made their peace with it many years ago and mostly seem to keep their mouths shut and have a great time. As a long time professional sound mixer I've certainly had to come to grips with lousy mixes in bands I've worked in, but we all have issues. 😎

I found time to try test onboard preamp builds with a couple of new DigiKey DKRed boards this week:

The bottom one, a three bander,  is now living in my fretless Marco Bass. I also tested my little mini-mix board yesterday, it works just as expected.

23 hours ago, Happy Jack said:

Which piece of gear would you run a mile rather than buy?

 

Anything made during the last century unless it's an acoustic instrument.

4 hours ago, uk_lefty said:

I'm going to can the idea of sending this bass by any courier. Dont be surprised if it turns up in a specialist bass shop soon. A specialist shop will have wider reach, better dealings with couriers than me, and will give a level of buyer assurance that I can't as a private individual. That's today's idea. 

 

 

 

 

 

When I needed to ship a valuable old bass to The Netherlands from the US I just took it to the most well known uptown bass shop in Seattle and had them pack it for me, for which they charged me a whopping $40. Then I went down the street to the post office that they use frequently, and those guys were completely on top of it. It made for a 12+ hour day since I had to get a CITES inspection along the way, which would no longer be necessary, but I got 'er done and everything went as smoothly as one might hope for.

I used one like this for many years: https://www.etsy.com/listing/963058918/vintage-vanity-case-vintage-samsonite?gpla=1&gao=1&&utm_source=bing&utm_medium=cpc&utm_campaign=shopping_us_all&utm_custom1=_k_0a0a7ae6d1b610669c7e1a7393761fe7_k_&utm_content=bing_319339186_1310617986645934_81913644654434_pla-4585513245482005:pla-4585513245482005_c__963058918&utm_custom2=319339186

But not for that stupid money, it was like $5 at a thrift shop.

Simple gain stage/clean boost with variable gain via trim pot:

I've done a matching mix/blend board as well, both will go up on OSHpark soon as free shares.

4 hours ago, Killed_by_Death said:

 

Always adjust the strap from a seated position, that way when you stand up, it will still be in the same place.

 

What if you never play sitting down with a strap though? It’d have to be crazy short to be doing anything in my case.

1 hour ago, Killed_by_Death said:

 

I had been looking at Mouser & only just noticed you can scroll to the right for more specs, DOH!

Looks like limited options, if you're not willing to buy in quantities of 100s.

 

The Bourns HRT (high rotation torque) variants don't have the same cheesy feel and physical noise as the cheaper Bourns carbon pots,  but AFAIK they only come in 24mm dia. / 3/8" bushing sizing.

18 hours ago, Killed_by_Death said:

Where can I get pots that are better than the bog-standard carbon-trace ones?

 

 

The Dunlop "super pot" seems to live up to its billing so far, but my sample size is a whopping one unit.