The Multi Amp aka Dynalo Mk2

[Pars]

Yes, it's 4,8 x 6,8, and latest rev is 1.5. What's input impedance of 'portable' Dynalo? If it's low, then problem is that 5K RK27114 Alps hard to source, even on Ebay (they seem to disappear completely).

 

I don't think the board will fit an Alps RK27 pot. Alpha or TKD 4CP-601. Not sure which the 1.5 board is set up for... because of the pinout of the Alpha, it is difficult to impossible to do both in the same space.

 

 

Sent from my iPhone using Tapatalk

 

[cspirou]

9 minutes ago, Helium said:

Yes, it's 4,8 x 6,8, and latest rev is 1.5.

What's input impedance of 'portable' Dynalo? If it's low, then problem is that 5K RK27114 Alps hard to source, even on Ebay (they seem to disappear completely).

It's relatively low. The pot shouldn't be higher than 10kohms

[Helium]

23 minutes ago, Pars said:

don't think the board will fit an Alps RK27 pot

Sh*t, I confused Alpha with Alps. Then TKD definitely better of course. Just place order for Alpha version, will contact PCB maker to replace Gerber.

[Kerry]

Those are the correct dimensions 

[Pars]

Not sure which version is for TKD... better confirm with Kerry though looking at the Gerbers would be easy to tell also. TKD = 3 pins per row; Alpha is 4 per row.


Sent from my iPhone using Tapatalk

[Kerry]

I believe they were both v1.5, but the TDK version had TDK in the name of the file.

[cspirou]

Anyone know what heatsinks are being used for the regulators on the Dynalo Mini?

edit:

found it. It's mouser # 581002B02500G

Edited September 10, 2017 by cspirou

[ginogino]

Hi everyone, I would like to assemble a preamplifier, using this project, the non mini version and buy this pcb:

http://www.ebay.it/itm/K-G-dynahibal-KG-Kevin-Gilmore-Unbalanced-to-balanced-preamplifier-PCB/132248796933?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m1438.l2649

The preamplifier, I did not use it for headphones, but as a preamp for a dac connected to a raspberry, I have already read that someone has written that has a friend who uses it as a normal preamp, there is no problem using it in this way.

The gilmore.chem.northwestern.edu site is no longer accessible, there is another source to find the files for this project.

[kevin gilmore]

Check stax mafia boards thread

[ginogino]

53 minutes ago, kevin gilmore said:

Check stax mafia boards thread

Thanks, but there is a treasure there.

[ginogino]

Hello to everyone, I'm a beginner and therefore, sorry if I say stupid things, and even for the bad English.

By now, I've already bought two of these cards:

http://www.ebay.it/itm/K-G-dynahibal-KG-Kevin-Gilmore-Unbalanced-to-balanced-preamplifier-PCB/132248796933?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m2749.l2649

believing they were the same (but with different arrangement of components) to the thread tab.

Comparing the ebay card with this (verse 1.02), I noticed that in addition to the positioning difference of the components, there are other differences, the resistances seem to be inferior and of different values, but most importantly, trimmers are missing from 10k positioned next to the that340 (which I seem to understand, are used to adjust the audio output), while there is the 10k trimmer, near the power input (this I did not understand what to do).

What I do, now, the lack of trimmers is a serious thing or I can go on with the pcb I've bought.

Where do I find the Gerbv file of the latest version of this card, not that with the smd components.

[Pars]

Take a look at the link in this post. https://www.head-case.org/forums/topic/11779-stax-mafia-circuit-boards/?do=findComment&comment=764131

Not sure what you are asking regarding SMD and non-SMD (through-hole)? I would look maybe at the 1.2 version, but check with a gerber viewer.

The ebay link that you provided is not the SS Dynalo but the unbal-to-bal board (not the same thing). It also isn't a dynahi balanced (auction title). Not even close.

Boards are so cheap to have made anymore that you would be better off to return these, and have some made from the proper gerber files.

Also note that the through-hole devices (On-Semi MPSW06/MPSW56) are discontinued, so not sure where you will find genuine parts of these... hence, the SMD version as those are available.

[ginogino]

23 minutes ago, Pars said:

Take a look at the link in this post. https://www.head-case.org/forums/topic/11779-stax-mafia-circuit-boards/?do=findComment&comment=764131

Thanks, I found the files, but they are in "CADCAM * .txt" format, with which software can I display them?

Yes, I know the MPSW06 / MPSW56 are difficult to find, but in their place, the L7815 / L7915 or the LM7815 / LM7915 are not okay?

[kevin gilmore]

find a gerber that works, gc-prevue or something similar

l7815/l7915 are voltage regulators, not transistors

[Pars]

Normally you just load the .zip file into a gerber viewer. I usually use https://gerber-viewer.easyeda.com, but there are a bunch of them out there.
And as Kevin mentioned, no on the 7815/7915 v-regs.
The SMD version would be the path of least resistance, and the device sizes used aren't bad at all to solder.


Sent from my iPhone using Tapatalk

[ginogino]

Okay, thank you all, but I managed to figure out how to create the file, to make me the pcb, the version I chose is kgdynalobal5, kgdynalobal9 is that with smd components.

How pcb, 2 or 4 Layers?

In the thread, it was discussed as replacements of components no longer production, of 7815/7915, so what can be used instead of On-Semi MPSW06 / MPSW56?

[mypasswordis]

2 layers. And maybe you are not understanding in English, so here is some broken Italian: 7815/7915 sono regolatori di tensione, non transistori. Non ci sono sostituzioni dirette per MPSW06/56 tranne SMD (PZTA06/56)

[ginogino]

18 minutes ago, mypasswordis said:

2 layers. And maybe you are not understanding in English, so here is some broken Italian: 7815/7915 sono regolatori di tensione, non transistori. Non ci sono sostituzioni dirette per MPSW06/56 tranne SMD (PZTA06/56)

The 7815/7915 I already knew them in the thread, someone mentioned these components and was definitely referring to the power pcb and I did not understand it.

One of these:

http://www.mouser.it/Semiconductors/Discrete-Semiconductors/Transistors/Bipolar-Transistors-BJT/_/N-ax1sh?P=1z0j3yaZ1z0y3jsZ1z0z63xZ1z0y4diZ1z0wa64Z1z0w9u0http://www.mouser.it/Semiconductors/Discrete-Semiconductors/Transistors/Bipolar-Transistors-BJT/_/N-ax1sh?P=1z0j3yaZ1z0y3jsZ1z0z63xZ1z0y4diZ1z0wa64Z1z0w9u0

it is not good to replace an MPSW06.

[Pars]

I'm not sure whether you could use the MPSA06/56 in this application? These are still available. Kevin might need to offer his opinion on that. These are rated at 625mW vs. the 1W for either the MPSWs or the PZTA SMD devices.

 

EDIT: not sure why my earlier edit didn't show up (user error?)

At any rate, I see that Arrow still has the MPSWs available in single quantities...

 

Sent from my iPhone using Tapatalk

 

[mypasswordis]

Just the output devices need to be the higher power versions, the rest can be TO92 package. 

[cspirou]

So what’s the story of the higher heat on the SS Dynalo Mini over the SS SMT Dynalo? Is it because the transistors are in a smaller area and there’s less copper to dissipate heat?

Or the circuit/layout isn’t the issue and the smaller enclosure just has less space for cooling?

[Pars]

I would guess it is because everything is in a smaller area and enclosure, thus less ability to dissipate heat.

[congo5]

What bias are you running?

I turned mine down by stacking another resistor IIRC

and have sinks glued to the top of transistors

There is lots of copper on Kerry's board but a limited amount of surface area to dissipate heat.

mine runs cooler in the case if I turn it on its side so air can rise vertically along the board surface.

But yes ..............in a tiny case it runs hot.

(from notes on ssdynalo mini)

255R bias +1.8k =223R

avg .280mv/20R=14ma  .28W

Edited October 25, 2017 by congo5

[cspirou]

I’m not running anything yet, just trying to understand a bit more before building. I have all the parts for the Dynalo mini but no chassis or heatsinks for the output transistors yet. I just know that in general people have been getting higher temps from the mini but it seems strange if the bias current isn’t higher then what people are running for the full size version.

I plan to do +/-20v like others have done, but might do 18v if it runs cooler.

[Pars]

I believe it is simple physics... smaller = more heat


Sent from my iPhone using Tapatalk