Random Questions For The Forum

[odourboy]

I have some questions for you guys - kind of all over the map...

1) What purpose does a Dumbleator serve and why do we need it?

2) Seems like the Eminence Patriot Red, White & Blue is one of the preferred D-clone speakers. What kind of cab does this work best in? (Any cab configuration that is NOT recommended?)

3) I've come across bits and pieces on preferred composition and even manufacturer of resistors and capacitors in various locations (like RN65 resistors on all plates and cathodes, ceramic for small (pF) values...) Could someone summarize the perferred list? (Sub-question... are Silver Mica caps bad? Why?)

4) What's the effect of using the 4 ohm tap for NFB versus the 8 ohm tap?

Thanks in advance! Let me repeat that I really appreciate the help you more experienced guys offer up to us novices.

Cheers, Brian

[Bob-I]

I have some questions for you guys - kind of all over the map...

1) What purpose does a Dumbleator serve and why do we need it?

It's a buffered effects loop.

2) Seems like the Eminence Patriot Red, White & Blue is one of the preferred D-clone speakers. What kind of cab does this work best in? (Any cab configuration that is NOT recommended?)

I like it, but I like the Celestions 12-65 more and recently I played through HiGain's Avatar cab with V30/G12H, it's amazing, I gotta get me one o dem.

3) I've come across bits and pieces on preferred composition and even manufacturer of resistors and capacitors in various locations (like RN65 resistors on all plates and cathodes, ceramic for small (pF) values...) Could someone summarize the perferred list?

Plate load resistors = high quality metal film. I like Vishay Dale RN65, Glasman like KOA SPeer but I haven't tried them.

Other resistors = 1 watt carbon comp

uF Caps = Metalizes polypropolyne. I like the Xicon MPP, others like the Orange drop PS6 series.

pF caps = ceramic, cheep one's. Buy a lot of them and throw away the leaky and out of tolerence one.

(Sub-question... are Silver Mica caps bad? Why?)

Simply cause they sound bad.

Recently a friend brought his amp over. I replaced ONE Mica with a ceramic and it was as if we took a blanket off of the speakers. We were both in shock over what a difference it made in the clarity and presence of the amp.

4) What's the effect of using the 4 ohm tap for NFB versus the 8 ohm tap?

It changes the amount of feedback. Both will work fine but you'll need to change the NFB resistor value. There's a calculator posted somewhere, I think in the files section, bottom line is the 8 ohm tap will require a larger NFB resistor to have the same effect.

[dogears]

Bob,

Glasman has always used RN65 on the plates. Always. Just saying. Carbon film everywhere else except cathodes which get a tight tolerence metal film. Maybe Koa there?? Doesn't matter IMO.

3) I've come across bits and pieces on preferred composition and even manufacturer of resistors and capacitors in various locations (like RN65 resistors on all plates and cathodes, ceramic for small (pF) values...) Could someone summarize the perferred list?

Plate load resistors = high quality metal film. I like Vishay Dale RN65, Glasman like KOA SPeer but I haven't tried them.

[heisthl]

I'm really suprised about the "Blanket over the speakers" comment on Silver-mica caps, my experience is just the opposite: The mica's make the tone too bright and sterile sounding and the ceramics add more character.IMHO
In the days before the internet when we had UseNet I remeber being excited about finding a bulletin board on trainwreck mods for Fenders. Almost all of the mods back then recommended replacing the ceramics with micas.

[Bob-I]

Bob,

Glasman has always used RN65 on the plates. Always. Just saying. Carbon film everywhere else except cathodes which get a tight tolerence metal film. Maybe Koa there?? Doesn't matter IMO.

I wonder why the de-gooped Dumble pics I've seen have monster resistors on the cathodes. I've tried several types and they don't seem to make an audable difference.

Glasman posted once that he likes KOA's. I just assumed he meant plate load. I stand corrected, gladly because it validates what my ear is telling me.

[drz400]

I'm really suprised about the "Blanket over the speakers" comment on Silver-mica caps, my experience is just the opposite: The mica's make the tone too bright and sterile sounding and the ceramics add more character.IMHO
In the days before the internet when we had UseNet I remeber being excited about finding a bulletin board on trainwreck mods for Fenders. Almost all of the mods back then recommended replacing the ceramics with micas.

Even though I agree that the SM isnt the best for me, I actually prefer the Ceramics I notice that Humble uses a lot of Silver Micas

[drz400]

Bob,

Glasman has always used RN65 on the plates. Always. Just saying. Carbon film everywhere else except cathodes which get a tight tolerence metal film. Maybe Koa there?? Doesn't matter IMO.

I wonder why the de-gooped Dumble pics I've seen have monster resistors on the cathodes. I've tried several types and they don't seem to make an audable difference.

Glasman posted once that he likes KOA's. I just assumed he meant plate load. I stand corrected, gladly because it validates what my ear is telling me.

Sometimes I think Humble just uses whatever he finds in the surplus stores. Even his new work doesnt contain a lot of new parts if ANY. But CA has a ton of surplus stores

[odourboy]

Thanks guys! I appreciate all your replies.

Nobody has ponied up an answer regarding the preferred cab for a Emi RW&B - Just looking for general direction - closed, ported (detuned) or perhaps 'Dumble Approved' oval open back.

Cheers!

[Pete]

I've experimented quite a bit with all combinations of the following speakers and cabs. Original EVM 12L, Celestion 12-65, Eminence Tonker, combo cab (open back oval), 2X12 open back oval, 1X12 open back oval and 1X12 ported closed back. I found that the closed back accentuates the low end a lot (too much for me), not too surprising. The most acceptable with the closed back is the EV. I have since lost interest in the Tonkers and have never tried the Red White & Blue. HTH

2) Seems like the Eminence Patriot Red, White & Blue is one of the preferred D-clone speakers. What kind of cab does this work best in? (Any cab configuration that is NOT recommended?)

Cheers, Brian

[dogears]

I have basically every speaker and speaker box design. My fave by far is my vertical 2X12, floating baffle, oval ported back Glaswerks. Similar to Robben's Dumble box. Loaded with 2 X Celestion G1265 Heritage reissues.

Incredible sound.

I recently heard a 2 X 12 Avatar closed back with the same G1265 speakers. It sounded really great as well, only with the 80s style voicing. 90s voice (HRM) was good but not as great as the oval port back.