Fender HRD Conversion to 2nd Generation (Hybrid)

[jam-mill]

Gutted my old (from 1995) Fender HRD and have begun the process to convert it to a 2nd Generation D-Style amp.

Fabricated some tube socket holders for the pre-amp tubes and made the board set.

[xtian]

Nice. I really like the HRD cabinet. I made my own 6G6B in such.

[M Fowler]

Start of a very nice conversion.

[jam-mill]

Any advice on what to do with the reverb tank?

Is there a tube circuit that can drive that 600 ohm input?

Sure would hate to have to use an IC...

[xtian]

A replacement tank is cheap; go with your favorite circuit.

[jam-mill]

Completed this build awhile back, but did not post a completed gut shot.

Also, the signal level into the phase inverter seems way too hot - any idea how to address this without affecting the overall tone?

This amp sounds really good when cranked up (as others have noted); albeit, a tad on the bright side.

Not sure if I should add snubbers or put in a treble bleed circuit. Any advice from those that know about the original would be greatly appreciated.

[jam-mill]

A replacement tank is cheap; go with your favorite circuit.

I built this (https://ampgarage.com/forum/viewtopic.p ... 13#p392013) to mount inside the cabinet.

[xtian]

This amp sounds really good when cranked up (as others have noted); albeit, a tad on the bright side

What's your plate voltage?

[jam-mill]

This amp sounds really good when cranked up (as others have noted); albeit, a tad on the bright side

What's your plate voltage?

B+1 = 287V
B+2 = 296V
B+3 = 411V
B+4 = 436V
B+5 = 438V

V1 - 12AX7
V1A = 195V
V1B = 202V

V2 - 12AX7
V2A = 200V
V2B = 202V

V3 - 12AT7
V3A = 283
V3B = 280

V4 = 434V
V4 cathode current = 31mA

V5 = 435
V5 cathode current = 29.4 mA

[xtian]

"A tad on the bright side" will probably sound a lot better if you can get the plate voltage down in the 350-400 range.

[jam-mill]

"A tad on the bright side" will probably sound a lot better if you can get the plate voltage down in the 350-400 range.

Aaron - thank-you for the information.

Any idea why the phase inverter input would be so sensitive?
Getting signal bleed even with the OD relay removed. Have also "chopsticked" to no avail... ;-(

[xtian]

The signal into the PI...when using the clean channel? OD channel?

If the clean channel is too hot, do you mean you get a lot of distortion from the clean channel?

[jam-mill]

The signal into the PI...when using the clean channel? OD channel?

If the clean channel is too hot, do you mean you get a lot of distortion from the clean channel?

There is no distortion, only that signal is reaching the phase inverter despite breaking the connection
to its input. Could it be a result of the dual-master set-up?

The problem is that even with the effects loop signal path broken there is still a significant signal bleeding
from the pre-amp into the power amp. The bleed is much more pronounced with the OD engaged.

[jam-mill]

"A tad on the bright side" will probably sound a lot better if you can get the plate voltage down in the 350-400 range.

One more thing - based on the information provided above, it would seem that the voltages on this layout (https://ampgarage.com/forum/viewtopic.php?f=4&t=12621) are incorrect; or, at the very least misleading.

[xtian]

There is no distortion, only that signal is reaching the phase inverter despite breaking the connection
to its input. Could it be a result of the dual-master set-up?

Ah, OK. To find what's wrong, we need to see the schematic you've used. Show me where you've disconnected the signal from the PI.