New Solid State FX loop source - $20

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MakerDP
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Re: New Solid State FX loop source - $20

Post by MakerDP »

Mine arrived yesterday.

It has an IRF830 and an LND150.

However it did NOT come with the threaded nut inserts on the Cliff jacks so I have no way to mount it as-is. I don't know if that was an oversight or if that is how they come. I will contact them Monday to find out.
Bob Simpson
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Re: New Solid State FX loop source - $20

Post by Bob Simpson »

My situation, exactly.
I've got some Cliff jacks I can steal the hardware from, but I would have paid them the extra buck for the parts.
How are they mounted in the Jet City amp?

Quick delivery, I will admit.

Bob Simpson
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MakerDP
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Re: New Solid State FX loop source - $20

Post by MakerDP »

yes quick delivery indeed.

I have not installed mine yet but my guess is that it is so light that just using the two jack nuts will be sufficient for mounting. I don't really see any other way to mount it.
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Re: New Solid State FX loop source - $20

Post by MakerDP »

Bob Simpson wrote: Tue May 09, 2017 4:13 pm
I've got some Cliff jacks I can steal the hardware from, but I would have paid them the extra buck for the parts.

Bob Simpson
Good news!

At my suggestion, AES has ordered and will now stock the following parts:
http://www.cliffinc.com/products/jackso ... L14218.pdf
http://www.cliffinc.com/products/jacksockets/CL1432.pdf

They will be parts numbers S-H960 and S-H961. I would imagine it might take some time to get them in and available on the website for ordering.

Pictures of them are near the bottom of this page:
http://www.cliffinc.com/products/jacksockets/s4.htm

The nuts are plastic but I figure that's ok because the jacks will be on the back of the amp anyways. It would seem that Cliff does not sell the metal insert nuts separately! We are on our own for the fibre washers though. I imagine just any old metal washer of the correct size would work.
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Gainzilla
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Re: New Solid State FX loop source - $20

Post by Gainzilla »

Hey guys,

Apologies for not checking in on this thread. As far as I know, the loop is as it's always been an IRF830 send and LND150 return. I've mentioned the possibility to improve the loop for better performance but I think it's pretty low on Doug's priorities. He's a one man show, quite literally. Anyway, the loop is a pretty good value as long as you understand it's unsupported and that you'll need to add nuts to the list of materials. ;)

Here is the schematic (can't remember if I already posted).

Cheers!

- Bryce
JCA20HV.3.jpeg
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MakerDP
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Re: New Solid State FX loop source - $20

Post by MakerDP »

Gotta say I'm a little disappointed. The instructions were sent, but clearly state a drilling guide is included in the package - it's not and there is no template in the instructions either, or even a center-to-center dimension of the jacks. Also, the person who responded to the email said he had absolutely no idea what I was talking about concerning the Cliff jacks' chrome insert nuts (the instructions also clearly direct you to mount the board with the included hardware.) There is simply no other way that I can see to mount the board.

I will be able to get the nuts from AES (well, a functional replacement anyways) but for their guy to not even have a clue what I'm even asking about and telling me I got everything that was intended to be included is a little off-putting especially when the instructions he sent me clearly state there are other included items.

I sent a friendly email stating what I feel is missing and why it's a kinda a big deal that the required mounting parts are not there and are not easily obtainable. We'll see what comes of it.
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Re: New Solid State FX loop source - $20

Post by Bob Simpson »

I don't have time for this.

No hardware, no drilling diagram, no wiring diagram.

Does anybody want to buy a fine loop with no documentation, and no mounting hardware for $25 bucks and the same kind of stick in an envelope and wrap it with tape free shipping they gave me?

I'm losing money on this one.

Bob Simpson
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Re: New Solid State FX loop source - $20

Post by Gainzilla »

Hi Bob,

It's a bummer that the loop isn't working out for you. If you still have it, and still want to give it a try, I can probably get you the drill guide. Did he send you install instructions?

Cheers,

- Bryce
I know it's only rock and roll, but I like it!
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Re: New Solid State FX loop source - $20

Post by MakerDP »

Install guide they sent me does not have any drilling info. Cust Service guy is looking into the Cliff jack nuts issue and the drilling info for me.
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Re: New Solid State FX loop source - $20

Post by Ten Over »

The question about the B+ was asked more than once, so I looked for a limiting factor on the schematic. If the 47K on the IRF830 Source is 1W, the maximum voltage it can take is 216Vdc. I don't own an IRF830 to test, but the Gate is probably around 218V if the Source is 216V. The 1M : 10M voltage divider will make it about 238V on the power rail. 216V across 47K is 4.6 mA and the LND150 will bring the total consumption up to an even 5mA. 5mA across the 10K/2W dropping resistor is 50V. 50V plus 238V is 288V which is the maximum B+ before the 47K exceeds its 1W rating.

Another thing to note about the IRF830 being biased so hot is that it doesn't have far to go before it clips. If the power rail is 238V and the IRF830 is idling at 216V, the theoretical maximum positive signal swing before clipping would be 22V peak. At lower B+ voltages the headroom is even smaller. So why the 1M : 10M voltage divider? The input impedance is the 1M resistor in parallel with the 10M resistor, so maybe it is to achieve a high input impedance. But a 1.8M : to 1.8M divider will give the same input impedance, take the strain off of the 47K resistor, allow a higher B+ voltage (which the LND150 needs), and reduce the current consumption by nearly half. Of course now the negative side of the signal will clip at about the same peak voltage as with the 1M : 10M divider, so there is little to no improvement in headroom. Maybe I'm missing something here, but If I weren't concerned about headroom I would certainly choose the 1.8M : 1.8M divider.
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Re: New Solid State FX loop source - $20

Post by Bob Simpson »

Bryce,

Thank you for the offer. You've been ahead of the nice curve the whole time.

I looked back, and not once was there a picture of mounting hardware anywhere.
The website clearly states no support. I should have believed them.

Anyway, I've given the loop, and the schematic you so kindly provided to a buddy of mine. I think he's going to jury rig it into a Peavey he's got.

Thanks again.

Bob Simpson
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Re: New Solid State FX loop source - $20

Post by MakerDP »

Here is the installation guide they sent me. It's a good guide and will certainly get you to where you need to be with the loop but on page 3 it does make these two statements...

"Measure and mark where to drill (or use the attached drill-guide)"

-and further down the page-

"Securely fasten the loop inside your amp's chassis using the included washers and nuts"

They sent me the instruction guide at my request because the website DOES say they will do that.
There is no "drill-guide" and there is not even a center-to-center measurement for the mounting holes which is just as good as a drill-guide in my mind.
There are no washers and nuts.

No support to me means they won't walk you through the install over the phone or even via email. I am totally cool with that since I know what I'm doing. I can even figure out how wide apart to make the holes with my digital calipers.

However, stating it comes with parts that it does not come with - oh and you can't even install it without them - now that is a deal-breaker for further business in my mind.
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Re: New Solid State FX loop source - $20

Post by MakerDP »

Ten Over wrote: Tue May 23, 2017 12:02 am The question about the B+ was asked more than once, so I looked for a limiting factor on the schematic. If the 47K on the IRF830 Source is 1W, the maximum voltage it can take is 216Vdc. I don't own an IRF830 to test, but the Gate is probably around 218V if the Source is 216V. The 1M : 10M voltage divider will make it about 238V on the power rail. 216V across 47K is 4.6 mA and the LND150 will bring the total consumption up to an even 5mA. 5mA across the 10K/2W dropping resistor is 50V. 50V plus 238V is 288V which is the maximum B+ before the 47K exceeds its 1W rating.

Another thing to note about the IRF830 being biased so hot is that it doesn't have far to go before it clips. If the power rail is 238V and the IRF830 is idling at 216V, the theoretical maximum positive signal swing before clipping would be 22V peak. At lower B+ voltages the headroom is even smaller. So why the 1M : 10M voltage divider? The input impedance is the 1M resistor in parallel with the 10M resistor, so maybe it is to achieve a high input impedance. But a 1.8M : to 1.8M divider will give the same input impedance, take the strain off of the 47K resistor, allow a higher B+ voltage (which the LND150 needs), and reduce the current consumption by nearly half. Of course now the negative side of the signal will clip at about the same peak voltage as with the 1M : 10M divider, so there is little to no improvement in headroom. Maybe I'm missing something here, but If I weren't concerned about headroom I would certainly choose the 1.8M : 1.8M divider.
In defense of the loop... if you wanted to tweak the values it most certainly is manufactured in a way that swapping any component on the board with another value/rating can be done very easily.

Once I actually get it installed in an amp I can let you guys know how it works. Might be a couple weeks though... I have a kid graduating from high school and another graduating from college... on the same day... this Thursday... lol
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Re: New Solid State FX loop source - $20

Post by sonicmojo »

The Jet City manual is incorrect. The middle pin is most definitely ground, the pictures we posted earlier are correct.

I came back to this thread today since I just killed TWO of these trying to get them to work in a higher gain Marshall type amp I've built. Before I did whatever I did to kill each of them (the main chip I'm guessing as I get 200V on all three pins now) I was getting a significant boost and creating oscillations in my signal chain. I had tapped a higher voltage (approx. 300V) source so maybe that was the problem as I think I was using something much smaller when I had success in a different amp. I may order I couple of new chips and try to repair them and figure out what was going on when I get a chance.

Bryan
---------
Bryan
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Re: New Solid State FX loop source - $20

Post by Ten Over »

The only way I have ever damaged a MOSFET was when I exceeded the gate to source voltage. If you are going to order new MOSFET's, you might want to consider STF7N60M2. It has internal zeners from gate to source, same pin-out as IRF830 and same price.

If you are ordering parts, you also might consider changing the 10M resistor to a 4.7M and changing the 47K to a 2-watt variety. The 4.7M will allow a much larger signal swing for the send before clipping. A 2-watt 47K resistor will allow the use of higher B+ voltages.
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