What upgraded parts are worth the extra cost when building an amp?

[SnickSound]

Was looking at those 5$ each blue caps from Sozo and it made me wonder: what upgrades are actually worth it?

I've built amps where I went all out, but also other from cheap surplus store parts, and after some tweaking of the circuit they all ended up fine (unless the output transformer was a 125-series).

But maybe I'm missing out on some extra mojo.

What "upgrades" have you found worth the extra cost?

I do know that for a higher gainer (SLO-level of gain), a big metal film resistor on the first plate takes the hiss down noticeably. After that though, it hardly seems to matter.

[SnickSound]

Sounds like the tranny is. I would be interested in knowing what readily available tranny do you upgrade to for 125 Series. Sorry I hope I didn't hijack and it ends up being all about trannies.

Hahaha, no problem.

Depends how/why you were using a 125-series. Typically they are coupled with 1-2W dual triode power amps, and there aren't a lot of options for that. I really wish Hammond would release something based on the Marshall 1Watters.
Magnetic Component does make one with a fixed 25k primary impedance, but I have no experience with it so I can't comment. I can't find specs either to see if inductance is significantly improved over a comparable 125C.

But where I did do a comparison was when I was running a pair of 6K6GTs. I found that around 8-9K is where I liked them but like all circuits I've built with a 125-series, it was harsh and lacked bass. So I put a 38$ Hammond 1750PA in its place (18W OT), and that helped a lot. It did not dramatically change the character of the amp, but the harshness was replaced with nice complex mids and a round low-end.

[sith]

Was looking at those 5$ each blue caps from Sozo and it made me wonder: what upgrades are actually worth it?

I've built amps where I went all out, but also other from cheap surplus store parts, and after some tweaking of the circuit they all ended up fine (unless the output transformer was a 125-series).

But maybe I'm missing out on some extra mojo.

What "upgrades" have you found worth the extra cost?

I do know that for a higher gainer (SLO-level of gain), a big metal film resistor on the first plate takes the hiss down noticeably. After that though, it hardly seems to matter.

dude you're poking hornet's nest
nevertheless, IMHO tranny and speakers have most impact on sound 

[jjasilli]

Caps in the signal path. 

[tubenit]

Output transformer,  speaker and caps.   

I don't think of this in terms of "upgrading" and adding expense but more in that I will go to the trouble to select specific  OT, speakers and caps that I know will help towards the tone I want.

With respect, Tubenit

[SnickSound]

Caps in the signal path.

"Technically", all caps are in the signal path (baring relay or filament power supply of course)

[jjasilli]

For once, I wasn't being technical. 


However, do feel free to upgrade them all. It is doable to replace all electrolytic filter & cathode bypass caps, e.g., with plastic.  Though that is not what I was suggesting.  However I do like to use small value cathode bypass caps like 1uF in preamp stages; and do use use plastic for that.

[pullshocks]

You're scaring me.  I'm about to do a Hoso + effects 6bm8 build with a Hammond 125E.

[mresistor]

The speaker is worth the upgrade.

[SnickSound]

You're scaring me.  I'm about to do a Hoso + effects 6bm8 build with a Hammond 125E.

Hahaha, it's not the end of the world, it's just not a great OT. It's only rated down to 125Hz after all.

I'm unfamiliar with the 6BM8. What primary impedance and power level are you going for?

[SnickSound]

dude you're poking hornet's nest
nevertheless, IMHO tranny and speakers have most impact on sound 

Speaker (and cabinet) is a definitive yes indeed. An amp is after all just a big power supply feeding a speaker, what you're hearing is that speaker.

But also, a good tuner (is it just me or are DIY amp demos on Youtube always suffering from really badly tuned guitars?)

[tubenit]

On my HoSo56 "the Minimalist" with 6BM8 tubes, I used a Deluxe 5E3 type OT.

Tubenit

[SnickSound]

On my HoSo56 "the Minimalist" with 6BM8 tubes, I used a Deluxe 5E3 type OT.

Tubenit

That's a good option

In Hammond-land, a 1750E/1760E (depending on if you want multi-secondaries) would be a nice option at 8.5K

The 1750Z has a 10K primary if required (but single 8 ohm secondary)

If one desires something around 12K, then you can always mismatch a 6K OT (e.g. 8 ohm speaker into 4 ohm tap)

Now, some might argue that these will be too big and won't saturate. But trying to get OT saturation in single-digit power amp is part of why they often end up sounding "small".