JDinPA17603 Messages: 69 Registered: May 2018 Location: Lancaster, PA
Member
Ok, got a Hustler head out of a "destroyed" 4x10 combo. Issue no reverb tank. Searched the forum...first step right?...and ran into a quandary. Differing recommendations for the suitable replacement. I know the tanks for the metal face amps have different impedance than the plexi amps because they are fed by an op amp ic instead of discrete transistors. I know the output impedance should be 2250 ohms that is a B code for Accutronics pans so my part number is complete except for the discrepancy with the input impedance. One recommendation is F- which is 1465 ohm impedance the other is B- which is 150 ohm impedance. So my question is what do I really need? Help.
4FB3C1B or 4BB3C1B
Both are type 4 with long decay (yep that is what I want) input isolated output grounded no lock open bottom horizontal mount.
Thanks in advance. A reply from someone with a Hustler that has successfully replaced the pan would be great.
Steve? Bill? Anyone?
Old Us Navy Vietnam Vet
Playing for my own enjoyment and irritation of the neighbors.
stevem Messages: 4743 Registered: June 2004 Location: NY
Senior Member
The input resistance is 57 ohms on those post 1970 reverb tanks.
If I am not mistaken a 4FB3D1B was the deal, so you need a tank with a1475 ohm input impeadance.
JDinPA17603 Messages: 69 Registered: May 2018 Location: Lancaster, PA
Member
Thank you for the info Steve. I am ordering up one today. Did notice that the one you list has both input and output isolated so should I run a ground from the can to the head? Thanks again.
As a test I hooked the head up to my 2x15 D130F cab and that thing roars! Sounded almost as loud as my 250.
Thanks again.
Old Us Navy Vietnam Vet
Playing for my own enjoyment and irritation of the neighbors.
I've got a Hustler chassis that I rebuilt that I love. Someday I'll either find or build a cabinet for it, maybe with 2-10".
The reverb is driven in current mode by the opamp so the input of the tank must be isolated from ground. If you look at the schematic, you'll see that the tank is part of the feedback loop of the opamp and is isolated from ground by a small value resistor (47 ohms maybe?). The output of the tank should be grounded to the case as is normal in most amps.
JDinPA17603 Messages: 69 Registered: May 2018 Location: Lancaster, PA
Member
Thanks for the input Bill. My brain is drizzling away in old age ... should of looked at that schematic first. They already shipped the isolated in/out so I'll deal with it when it gets here. For $75 for the amp head and $25 for a new pan it will be sweet. Now if I could just find me a tuck n roll person with reasonable rates 🤪
Old Us Navy Vietnam Vet
Playing for my own enjoyment and irritation of the neighbors.
stevem Messages: 4743 Registered: June 2004 Location: NY
Senior Member
Just remember that when you mount it the output side of the tanks needs to be as far away from the power transformer as you can get it if you want minimal hum.
And in that same vein the cables should be well made in the shielding dept.
JDinPA17603 Messages: 69 Registered: May 2018 Location: Lancaster, PA
Member
Steve, no issue with the tank and transformer hum with the head being a Hustler from the combo the pan is external to the amp and the amp itself is enclosed. After talking with Bill an looking at the schematic is ordered a 4FB3C1B as the schematic shows the pan going to ground. Ordered it through Amplified Parts...that website is quite a resource, especially with regard to reverb pans. Thanks again to both of you for your help. I will be using high grade RCA cables with the new pan.
Old Us Navy Vietnam Vet
Playing for my own enjoyment and irritation of the neighbors.