Well I placed my order with Mouser and Antique Electronic supply today for my parts and Tone Caps respectively. I went with the Metal film RN65 for plates and the PS OD caps for the tone caps per the boards recommendations.
I still need to order iron. Do people use the Marshall 50wt PT (over Fender)because of the higher amperage rated filament winding so you could use 6L6 or EL34's? I was planning on using Fender Bassman replacement iron.
So I'll ask the question......do the best sounding clones have EL34's or 6L6's??? At this point I can still go either way....
keithrick wrote:
I still need to order iron. Do people use the Marshall 50wt PT (over Fender)because of the higher amperage rated filament winding so you could use 6L6 or EL34's? I was planning on using Fender Bassman replacement iron.
I am betting that the Marshall is more often used as it is easier to mount. Of course YMMV.
So I'll ask the question......do the best sounding clones have EL34's or 6L6's??? At this point I can still go either way....
Use 1K screen resistor and you can swap out at any time. Of course, with the appropriate bias change.
Gary
Located in the St Croix River Valley- Afton, MN
About 5 miles south of I-94
aka K0GWA, K0 Glas Werks Amplification www.glaswerks.com
Hello all, I have decided to go with the Bassman Iron. Just got it from AES. I have a few questions regarding the choke and transformers....
1. Should I just get the standard replacement Choke for BF/SF fender equivalent to #125C3A and #022699 or is there a better choice for the Dumble set up? It shows 90mA DC.
2. Same for the Reverb Transformer- equivalent to #125A20B and #022921. 2.5K primaries and 8ohm sec.? Will this be compatible with the standard Bassman Iron?
3. For Relays I ordered 551-MR62-12USRY from mouser, DPDT 12V low signal relays. Excuse my ignorance but will these allow me to control 3 options? i.e. Channel/Boost/Rock-Jazz or any combination I choose? I intend on using the Rat shack transformer.
Thanks in advance for any comments! BTW- I am getting the wife a Digital Camera today for mothers day....should be able to post some pics this build!
I used a 125C1A for the choke. The reverb tranny is the same one.
As for the relays, any place you use a switch, you can use a relay. The RS transformer should be fine as long it's rated high enough to power the relay coils. The 12V 450mA tranny should be plenty big. Channel and Boost are good choices. R/J is probably a waste. (Trust me, you'll never use it.)
Many excellent Dumble-inspired amps do not use a choke at all. They have a cement resistor instead. Usually around 500 ohms for a 50W, 250 ohms for a 100W.
You may consider this - or make it switchable between the choke and the resistor...
I've seen the substitution of a resistor for the choke referred to as the "Ford Mod" on the rumor that his Dumble does that. However true or not, adjusting the values of the resistor, say between 250-500 ohms, will nicely alter the behavior or response of the amp to playing, which I think is referred to as sag and has been discussed on the forum. I find it to be a really nice tweaking point. I agree with Norm, the Rock/Jazz switch is soon to be hard wired to Rock on my amp to free up a switch for something more useful.
Thanks for the info guys. I am probably going to use both Choke and Resister and make it switchable. What wattage rating does the resister need to be? ...around 25 watts like on the Express?
The rock/jazz switch might not make the cut bassed on everyones opinions! I didn't use it much on my previous Fuchs mod either.
keithrick wrote:Thanks for the info guys. I am probably going to use both Choke and Resister and make it switchable. What wattage rating does the resister need to be? ...around 25 watts like on the Express?
The rock/jazz switch might not make the cut bassed on everyones opinions! I didn't use it much on my previous Fuchs mod either.
Considering the post choke current is pretty low a 10 watt cement is fine. I used a 10watt in my Superchief amp (express clone) and it works fine.
Gary
Located in the St Croix River Valley- Afton, MN
About 5 miles south of I-94
aka K0GWA, K0 Glas Werks Amplification www.glaswerks.com
Welll the parts are starting to trickle in! Only thing I am waiting for are iron and tube sockets.
I am bending up a chassis like Bob-I did 20x8x2.5 and wanted to solicit a few opinions...
1. Should I mount the trannies like the Fender Bassman? Or both on one end ala Trainwreck. It appears from the pics I seen HAD mounted the iron like Fender did.
2. My amp will be based on the Latest layout by Normster incorporating all of Scott's suggestions. (Thanks guys) I have three relays and intend on having a 3 button footswitch. So the question of the hour for you is what should be footswitchable? I am thinking Channel, Mid Boost and Boost. Any better options to consider with this layout?
I am planning on bending the chassis this Wednesday! Building this weekend!
Save for the iron and 2 pots I'm ready to start on my 2nd. I plan to have 3 footswitchable things too - OD, PAB, and HRM. I'm planning to use a 5-pin XLR for the footswitch connections. I think there is a Marshall-replacement (unbranded) 3-switch footswitch from AES/CEDist for around $20-$30. LEDs are already there too, if the picture is true.
I went with the Metal film RN65 for plates and the PS OD caps for the tone caps per the boards recommendations. 
but will these allow me to control 3 options? i.e. Channel/Boost/Rock-Jazz or any combination I choose? I intend on using the Rat shack transformer. 
I didn't use it much on my previous Fuchs mod either.