Yes, I did try to measure the DCR value of the stock coils. But, I could not get an accurate reading even with two coils wired in series.
My digital ohm meter could read a resistance value that low....
Type: Posts; User: Baron030; Keyword(s):
Yes, I did try to measure the DCR value of the stock coils. But, I could not get an accurate reading even with two coils wired in series.
My digital ohm meter could read a resistance value that low....
Wow $ 98 or higher..
Polonium has a half-life of about 6 months. So to effectively take full advantage of this product, replace the cartridge at least annually. Every six months is even better.
Very nice work!
Can you share with us the source of that lovely the ivory grille cloth?
Baron030:)
Has anyone had any experience with a Ashly Protea Digital Speaker Processor?
What is your impression of it's sound quality?
And how does it compare with other Digital Speaker Processors out...
Yes, you really need to do your tests with the driver attached to the horn you plan on using for your project.
The horn is going to put an air load on the diaphragm and that is going to effect the...
Hi Bumba
I did a little looking around and it appears that 1.4 mH is not a stock off the shelf size. Which means that if you were to replace your existing JBL coils, you most likely need to order...
Hi
In the 030 system, the crossover network is rather simple and historically the main differences between the 16 ohm and 8 ohm versions has been the inductance value of the coil feeding the D130...
I recently did a 4311b overhaul. To remove cover plate (foilcal) you use a hair dryer and thin putty knife blade or scrapper and work slowly. It may take a good 15 to 20 minutes to get the adhesive...
I thought that I should follow up and thank everyone for their help. Jbl4ever was very helpful in posting the service manual, which clearly shows that removing the foilcal is required. And...
Hi Pyonc
Looking through the manual, your amp has two fuses. Since, you are living in the state of Maryland. I can assume that you are running this amp with 115 volts. So, the 3/10AMP fuse is...
I have a pair of JBL 4311B speakers that are in pretty good condition.
But, I need to replace the L-Pads. And while I am at it, I plan on replacing the capacitors as well.
And the grill cloth has...
Hi
The box appears to be home made and nicely built.
But, before you reinstall the drivers, you should measure the inside dimensions and size of the port.
To me, the port looks too large.
So,...
If you can't find a coil with the required inductance value then order a coil with a slightly higher inductance value and then remove a few windings from it. But, it will require you to have an...
Your D-45 should be like the D-75A, and converting the amp from stereo mode to bridged mono is not a big deal. In the case of the D-75A, there is a small PC board pin “jumper” that must be moved and...
You could add a Balanced Line Receiver chip before the first TL072 and a Balanced Line Driver chip after the second TL072.
Links to some very fine balanced line chips:
...
Hi Ed
There are multiple versions of WinISD on the linearteam web site.
And some versions work better than others.
I have found that the older versions don't work well on the Windows 7.
...
Hi Rob
Wow, you are hitting, your project with a lot more design tools than I used for port tuning a project. Of the two most popular tools, of course I am referring to WinISD and Bass Box 6. I...
Hi Rob
A sealed enclosure has only one impedance peak and a bass reflex enclosure actually has two impedance peaks, with one peak above and the other peak below the port tuning frequency. A valid...
Wow, I am having second thoughts. And I hate to have to say this. But, I really don’t think you have enough knowledge and experience working with electronics to safely test and possibly service your...
Hi Pyonc
Well, maybe I am not very clear in my explanations. Fundamentally, we are testing to see just how much DC voltage would be going to the speakers when no input signal is present. So, the...
Hi pyonc
Rather than respond to your private email, I thought it might be better to post to the thread, as more people may benefit from it.
The Fluke multi-meter is the correct tool for the job....
After reading the JBL service manual, as long as the DC voltage is below +/- 0.1 volt the amplifier is OK. And a little thump is not a problem. But, if you measure a higher DC voltage than it is time...
Hi pyonc
Yes, the thump does have to do with it being a “T-Circuit” amplifier. You can think of the “T-Circuit” as being a discreet component version of a modern integrated circuit op-amp. It is...
Hi
I did a quick google search and I could not find the JBL SA640 schematic. But, I did turn up the service manual for the SA600 and SA660 amplifiers, which should be very similar to the SA640....
I agree the manual looks very blurry. But, to me the font looks to be Italic. So, what appears to be a “7” could very well be a “T” instead. And my google searches do not turn up any 71084 or 7L084...