Tube Amp Archive

Can I just change the cathodes to 2.7k/.68uf on V1 pin8 and 1.5k/22uf V1 pin3 along with adding a 33k to the input without doing the voltage divider? What effect would this have ? What is the pupose of the voltage divider and how would you implment it on a turret board without adding turrets? Keithr...

Yes I used a .0022 cap in that postion. Smallest in physical size. Thanks for all your help Paul I appreciate it!!

I have clarostat pots and they are not scratchy. This is my first amp build so I have 2 newbe questions

1. Which cap(s) is that in this layout ? I know it is the part of the circuit feeding V3. 47pf mica to a .002uf?

2. What value would you use?

What would cause a trainwreck to have flabby sounding bass? I have Tung Sol preamp tubes and Winged =c= el34 power tubes biased at 33mv. I have tried biasing as high as 43mv with the same results. Using a new avatar 2x12 openback with vintage 30 and G12H30 speakers. Sprague atom and mallory 150 caps...

I used a .090 aluminum that was used for traffic signs that we make at our garage. I made mine longer than the chassis so I could drill holes in the extra length for mounting the chassis in a cabinet. The plate must cover the complete bottom of chassis to provide shielding.

I am using the 600 series PVC polyester caps manufactured by CDE/Mallory. I do not care about the correctness of this build . Just looking to improve the tone .

Finished my wreck and have it up and running. Amp is fairly quiet for the amount of gain on tap . Followed Niks layout and gounding scheme for this amp. Going to redo my grounding scheme following rhison suggestions in this thread https://tubeamparchive.com/viewtopic.php?t=1287 I find the amp overly...

What grounding changes would you make to this layout.I have clarostat pots in my build and buss wire on pots is not an option.

I am getting ready to wire up my Paul Ruby output transformer and have a wiring question. It only has a Primary Impedance 5200 connection with a color coded wires of Green ,Blue, and Purple . Paul Ruby said that the blue is the CT and that the plate leads are the purple and green.Which tube socket d...

Nice clean build. Great tone and feedback.What tubes did you you use for this express?

I in the process of building an express with Paul Ruby's Heyboer transformers . Here are the specs on them from Heyboer. Tim, HTS-5199 Primary 120 volts Black Leads Secondary: 300 - 260 - 0 - 260 - 300 @ 300 mA Yellow -Yel/Grn -Yel/Red - Yel/Grn - Yellow 6.3 Volts CT @ 7.5 Amps Brown - Brown/White B...

I am in the process of building an express with a set Of Paul Ruby's Heyboer transformers here are the specification I got from Heyboer Tim, HTS-5199 Primary 120 volts Black Leads Secondary: 300 - 260 - 0 - 260 - 300 @ 300 mA Yellow -Yel/Grn -Yel/Red - Yel/Grn - Yellow 6.3 Volts CT @ 7.5 Amps Brown ...

Allynme thanks for the info on the pin location ,already have the jacks and resistors.Thanks for the offer on the 20k 10 turns but I am just going to use the 50k 10 turn clarostat pot that I already have :wink: KGW thanks for the info .I looked over the Komet pictures and your suggestion would work ...

I would like to have a copy to please. THX!!

lheil at uiuc dot edu

Putting together an express and have some questions. I have an 50k 10 turn external bias pot that I will be mounting similar to the komet.The pot has three leads one on the end of the resistor,one in the middle of the resistor ,and the last one goes to ground.Does the top resistor one go to the 47k ...