Signal resistor type

[Bob-I]

Hi folks, it’s been awhile since I put together a Dumble style amp, I’m at it again.

10 years ago I used Vishay RN65 for plates and Xicon carbon film for everything else, cathodes, signal chain, etc. The RN65s weren’t all that when I last used them, and I’m looking for a consensus on what folks are using today.

The amp I’m building is based off the 183 schematic and using an aaelectronics PCB. I plan to stick with CF for signal, but I’m stumped on the plates. I want to use new components, not NOS for cost and ease of purchase. I know I’ll get as many opinions as folks who comment, but I’m ok with sorting through all reasonable responses.

Thx in advance!

FYI, these aaelectronics PCBs are excellent quality. I just completed a Super Reverb and it sounds great

[dbharris]

Nothing wrong with 1/2 watt Koa Speers for the signal path:

https://www.mouser.com/c/passive-compon ... &instock=y

Of course 183 has metal film in the signal path, but understand you are wanting to use carbon film.

Plates...lots of options even just at mouser. Not to toot my own horn, but you may find this thread helpful https://ampgarage.com/forum/viewtopic.php?f=4&t=36562.

-Dan

[Bob-I]

Thx Dan. I actually found that thread, and I appreciate all your hard work. It left my head spinning.

I've used KOA before and like them, so maybe I'll grab some for the plates and see how it sounds. The good news is, these boards are built so solid you can desolder and resolder with almost no issues.

[jelle]

Hillsborough? You are very very local. Long time no see, last time was at Greg Buchalski's Ampfest. I sent a PM

[WhopperPlate]

Careful , can’t talk too loud about how koa resistors sound without starting a debate …

I like modern Dales on the plates . Bright yes but they feel bouncy and easy to play . I like to put them in just the overdrive portion of the circuit alone , or just v1, or both depending on the target tone .

I like xicon for later in the poweramp and koa early . xicon seem to be going the way of obsolete

[martin manning]

I smell them. KOA's smell strongly of crushed gravel, where the Dale's have a volcanic ash note ;^)

[Bob-I]

You guys are funny, I should come here more often.

My challenge was finding a vendor who stocked KOA of the values I needed, seems simple, but in the end I ordered Vishay's from AES.

[Bob-I]

So I ordered Vishay resistors from mouser, some look as expected, light blue and normal size for 1 watt, and some are tiny, the size of a 1/4 watt. The package and data sheet clearly state 1W so I’m confident they’re correct. I have everything I need for the preamp in the standard size, but the PI plates are the compact size.

Has anyone used these new compact package Vishay resistors? Any sonic issues I need to be aware of?

thx

[Fictitiousfreedom]

So I ordered Vishay resistors from mouser, some look as expected, light blue and normal size for 1 watt, and some are tiny, the size of a 1/4 watt. The package and data sheet clearly state 1W so I’m confident they’re correct. I have everything I need for the preamp in the standard size, but the PI plates are the compact size.

Has anyone used these new compact package Vishay resistors? Any sonic issues I need to be aware of?

thx

I had the same thing happen recently. All of the strange value 1 watt vishays i ordered, like 51.1k from mouser came in that new small package. I was going to use them but after starting to place them i ordered dales in the same values instead. The rational part of my brain says to not even admit this because it’s superficial but they just look so sad on the board to me, i wish the aesthetics within the amp didn't matter to me but they do.

Ive been using them in pedal builds, they are great for that but as far as sound in an ODS goes i cant help much. If you use them id like to know what you find though. I buy everything from Mouser in quantities of 10 so i have a few.
Sorry i couldnt be more help but i figured you or anyone else in the same boat can know that there is at least one other person who passed on them for aesthetic reasons, if that is your reasoning.

[GAStan]

Sorry i couldnt be more help but i figured you or anyone else in the same boat can know that there is at least one other person who passed on them for aesthetic reasons, if that is your reasoning.

Guilty as charged so I'm watching this thread with interest too.

[WhopperPlate]

I smell them. KOA's smell strongly of crushed gravel, where the Dale's have a volcanic ash note ;^)

I didn’t know you can hear with your nose . Crazy, you learn something new from every day

Sorry to say I haven’t tried the newer Vishay resistors , if I ever do I will give a report

[chaccmgr]

RG wrote a great article on resistors and their sound/noise and where to use and where not
http://www.geofex.com/ search for "Using the Carbon Comp Resistor for Magic Mojo" on the starting page