Search found 121 matches

by RB
Sat Sep 15, 2012 12:35 am
Forum: Dumble Discussion
Topic: Transformer selection for a 183
Replies: 19
Views: 2281

Re: Transformer selection for a 183

If you are thinking about the 183 because you liked the tone in demos of the real thing or very good approximations you should stick to the original formulation. That is a Twin PT, Marshall OT and 4 EL34s. IMHO the 183 is the best d-style for people looking for more contemporary rock and rock-blues ...
by RB
Fri Sep 14, 2012 6:21 pm
Forum: Dumble Discussion
Topic: Transformer selection for a 183
Replies: 19
Views: 2281

Re: Transformer selection for a 183

The Dynaco A470 you reference is an amazing OT. I have used it with 4X6V6, 4XEL84, pairs of 6L6s, and pairs EL34. It is my goto 50 watt OT. If you are building a 50 watt 183 then its a good choice. It has however the wrong primary impedance (4.3K) for use with 4XEL34s. You need something in the 1.5-...
by RB
Sun Aug 05, 2012 11:55 pm
Forum: Technical Discussion
Topic: Super in a Tweed Chassis
Replies: 8
Views: 1345

Re: Super in a Tweed Chassis

I am going to make the assumption you have 5E3 size cabinet and chassis. If my assumption is correct I would recommend the the Allen TP40D PT. It fits the 5E3 cutout and is used in his 40/35 watt amps. His TO35MT is a good OT if you are looking for a blackface sound. If you are looking for a more tw...
by RB
Thu Jun 28, 2012 5:04 pm
Forum: Dumble Discussion
Topic: Circuit configuration recommendations
Replies: 3
Views: 790

Circuit configuration recommendations

I have a friend that I am going to help with his amp build. He plays in a Carlos Santana tribute band and this amp will be used primarily for this application. He is going to fabricate the chassis and build the cab and I will do the electronics. I would appreciate any recommendations/suggestions reg...
by RB
Fri Jun 08, 2012 6:12 pm
Forum: Technical Discussion
Topic: Fender Blues Deville 212 rattle/ringing experiences?
Replies: 4
Views: 1549

Re: Fender Blues Deville 212 rattle/ringing experiences?

The phase inverter resistors on the tube sub boards would be a good place to start. Replace with a higher wattage good quality part. I have found many of these toasted/cracked many times on this series amp. I have also had bad filter caps on the preamp nodes display this condition on these amps. Reg...
by RB
Sat Mar 24, 2012 11:43 pm
Forum: Technical Discussion
Topic: PPIMV LOUD HUM
Replies: 39
Views: 10369

Re: PPIMV LOUD HUM

It seems that you have addressed most if not all the issues you could have with the master dual gang pot. Which brings me to you original post With the bright and normal volumes on zero and the PPIMV on zero I get a loud hum. With the PPIMV ON 10 the hum goes away. Nothing in the thread tells me you...
by RB
Mon Feb 27, 2012 7:56 pm
Forum: Technical Discussion
Topic: 40-Watt Blues Jr.?
Replies: 8
Views: 1359

Octal power section for BJ's

Check out BillM's web site - Octal power sections and transformer up-grades ideas for BJ's
by RB
Thu Feb 23, 2012 2:14 am
Forum: Technical Discussion
Topic: Half triode question...
Replies: 22
Views: 3270

Re: Half triode question...

If this were mine I would put the normal channel from a black face Deluxe Reverb in this chassis. I don't know what kind of PI is in this circuit but I am sure a long-tail-pair would drive the 6V6s harder. Use both halves of V1 ala Fender DR - You can use the existing front panel for the volume treb...
by RB
Tue Jan 31, 2012 1:13 am
Forum: Technical Discussion
Topic: Jupiter Cap Quesiton
Replies: 20
Views: 13074

Re: Jupiter Cap Quesiton

I have been using the yellow Jupiter's in early tweed circuits (parapahse inverters), Supro ThunderBolts and Ampeg M-15 style vintage era amps. I have a/b them against all current production caps and in these applications nothing sounds as good to my ears as the Jupiters

Regards
Randy
by RB
Wed Dec 22, 2010 12:35 am
Forum: Technical Discussion
Topic: I Needs A Nibbler!
Replies: 33
Views: 5681

Re: I Needs A Nibbler!

What blade/abrasive wheel for the Dewalt would you recommend to cut xfmr holes in a chassis ?
by RB
Wed Nov 10, 2010 9:33 pm
Forum: Dumble Discussion
Topic: Make room for one more...
Replies: 11
Views: 1589

Re: Make room for one more...

I have seen this guy flamed on ebay and another forum for advertising custom DC-30 amps which appeared to be Ceriatone kits with upgraded parts. All in all the workmanship looks to be very high quality on the pics I have seen. Makes you want ta know what the guy is smokin when he advertises amps wit...
by RB
Sun Oct 24, 2010 10:56 pm
Forum: Technical Discussion
Topic: Heyboer Trans question....
Replies: 11
Views: 3248

Re: Heyboer Trans question....

The Magnetic Components set you are referencing are not correct for a 5E7 build. The 5E7 OT is 6K and I have measured some that were 5.1k or there about. Mojo sells an accurate reproduction with 4 and 8 ohm taps. Also the choke you reference is a blackface style choke rated at 90ma intended to be in...
by RB
Sun Sep 12, 2010 9:07 pm
Forum: Dumble Discussion
Topic: Anyone tried D-style OD with 5E7 preamp?
Replies: 6
Views: 1038

Re: Anyone tried D-style OD with 5E7 preamp?

http://www.kilback.net/homebrewtweaks/amps/amps.htm#tweed5e7 Here is a link I ran into a few yerars ago. 5E7 with half of an overdrive section. May be of some interest to you. Some other 5E5/5E7 combinations of mods/circuits on site also. I built a 5E7 using KT66's and GZ34 and 3x10A125 Weber alnico...
by RB
Fri Apr 09, 2010 2:36 am
Forum: Technical Discussion
Topic: can anyone explain ....
Replies: 4
Views: 1160

Re: can anyone explain ....

The purpose of the split plate load is to decrease the signal level go to the next stage. I am sure you know that but just thinking outloud. So when you go to the top 47k with the coupling cap you are seeing the full voltage swing which makes the drive to the next stage greater. I dont think this is...
by RB
Wed Nov 04, 2009 10:41 pm
Forum: Technical Discussion
Topic: split load phase inverter
Replies: 13
Views: 4919

Re: split load phase inverter

Split load inverters turn up in a lot of interesting places. The Kelly amps, as noted above and the Orange 120 MKII driving 4 EL34s is another example. I have had the most split load experience driving 4 tubes with the Double Deluxe circuit. Victoria builds one and you can find a kit from Weber call...