mjn
New Member
Posts: 39
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Post by mjn on Mar 11, 2018 20:40:05 GMT -7
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Post by zpilot on Mar 12, 2018 8:39:45 GMT -7
I doubt you would like it. It's going to remove some of the compression that the amp has when you hit a note really hard. That was engineered into the amp on purpose. Doc could have actually built the amp cheaper with a SS rectifier but chose to go with a vacuum tube one. It would require a bias adjustment also for the amp to run correctly.
Where those really work well is in old Fenders to get more of a Stevie Ray Vaughn type of sound. I would not use one in ANY Dr.Z amp.
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Post by daddyelmis (Greg) on Mar 12, 2018 10:21:02 GMT -7
I tried one of these years ago in a Bassman RI. It worked fine but didn’t sound like a tube rectifier. www.tedweber.com/wz34
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Post by doctorice on Mar 12, 2018 11:29:19 GMT -7
I would not use one in ANY Dr.Z amp. Friendly amendment: except those designed with one
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Post by zpilot on Mar 12, 2018 12:12:46 GMT -7
I would not use one in ANY Dr.Z amp. Friendly amendment: except those designed with one I did not know that any were. Which ones please?
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Post by Chilly Gibbons (Todd T.) on Mar 12, 2018 12:48:14 GMT -7
Z-Lux and JAZ 20/40
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Post by doctorice on Mar 12, 2018 14:44:24 GMT -7
Also: Remedy, Surgical Steel, EMS (has both tube and SS), and Delta 88. KT-45 and 6545 may have had SS, possibly as an option. (Need to check my 6545)
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Post by zpilot on Mar 12, 2018 14:45:45 GMT -7
Yes. I understand that. I have a JAZ. I was referring to any amps having an octal SS module in the rectifier socket. My JAZ has the SS rectifier diodes inside the chassis so there is no socket for that. The EMS, I understand, has the ability to switch between the tube rectifier in the socket or an internal SS rectifier.
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bradm
Junior Member
Posts: 74
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Post by bradm on Mar 12, 2018 20:09:14 GMT -7
Assuming the "canned SS rectifier" is just a pair of silicon diodes across the gap, inserting that device will give you an increase of B+ and, for fixed bias voltages derived from B+, and increase there, too. Even those it's negative, it will be a negative potential difference. That difference will vary with respect to the drop a particular rectifier typically provides. Every amp's load will vary and, accordingly, any given tube rectifier's drop will vary, too. One chart circulating compares the tube rectifier's drop as compared to silicon diode use. At 425VDC (silicon) a 5U4GB might drop it to 375VDC or 50V difference. For fixed bis amps, that could turn -51V into -57 for the same voltage ratio difference, (425/375)x51 A 6V difference on a bias circuit is huge in current change. So, what will likely happen when you drop that SS rectifier in is...B+ will increase by some substantial amount...the bias voltage will negatively increase and the overall bias will be colder than wherever you had previously parked it. Thus, the SS insert is the safest direction to go if the current bias is set well. Now, to really know if you'll like the SS, you need to recheck bias and adjust accordingly (to warm it back up). HOWEVER...now you have to realize the B+ also increased, which will lower your bias current set point for calculating the same ideal plate dissipation. You "might" be back in the same ballpark? But, it's not a linear trade-off...you should measure current...the plate to cathode drop...and calc & set accordingly. You may find you're just fine swapping, but I wouldn't play it for too many minutes without checking it. Still, without rebidding...you really won't truly know if you prefer SS diode or not. Here's to safe swapping!
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Post by KeithA on Mar 13, 2018 3:20:55 GMT -7
Yes. I understand that. I have a JAZ. I was referring to any amps having an octal SS module in the rectifier socket. My JAZ has the SS rectifier diodes inside the chassis so there is no socket for that. The EMS, I understand, has the ability to switch between the tube rectifier in the socket or an internal SS rectifier. If I recall the KT-45 did. The spec sheet actually lists both ways. drzamps.com/product/kt-45/
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Post by zpilot on Mar 13, 2018 11:53:17 GMT -7
Thanks. I've never had an opportunity to see one of those.
Now that I have my memory in gear I believe I recall Doc saying that it is OK to use one in a MAZ SR, but not the other MAZ models.
I must confess that my preference for 5AR4 rectifiers over any others may have come into play.
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Post by mudman on Mar 13, 2018 13:35:39 GMT -7
Mini Z is solid state rectification as well
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Post by zpilot on Mar 13, 2018 13:58:23 GMT -7
No socket and plug-in module though, right?
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Post by mudman on Mar 13, 2018 15:49:00 GMT -7
No socket and plug-in module though, right? Correct
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Post by DeanG on Apr 9, 2018 6:24:20 GMT -7
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