Need help planning non-HRM build

[Tonegeek]

PT: Due to limited space I need to use a standup power tranny. I can use a Marshall style but prefer to get one with a tad less voltage, like the Fender ones. This will be a 50 watt, 6L6 amp. Also would love to use one with a bias tap.

OT: Seems like Bassman iron is the way to go. Am thinking Hammond or Heyboer, but they seem to only come with multitaps for 2,4,8 ohms. would love to find something with 4,8, 16 ohms though.

100k plates or 220/150, or hybrid? This is a biggy. The friend I am building for likes the Lerche Youtube clips and so we are using that amp as a baseline. Consensus is that it is a high plate amp. The amps with the best clean sounds (my opinion only) are 100k amps. I have heard great OD sounds out of low and high plate amps, so I am leaning toward building a low plate version but from what I have read, there seems to be some trade-off with the OD sound if using all 100k plates. Is there a good compromise to get sweet, harmonically rich cleans, and get a fat OD? Oh yea, and it still has to sound close to that Lerche vid (although that vid would not be my #1 choice for a baseline)! (Its going to be hard to keep in mind that it is someone else I have to please).

Lastly, I am building in a Dumbleator. In the non- HRM amps, the master is after the channel switching and before the loop. Anyone see any issue with leaving out the master altogether? In this case since the loop will always be in circuit, the loop send and return pots would act as masters. I will just move the return pot to the front panel and call it master. My only concern is will this change the tone much by not having the same load on the signal, especially in the clean mode? Potentially without the master, the signal would be higher going through the loop follower side than it would be if you kept the original master since you have an extra 1M to ground through the pot and also less because you might not run the original master wide open. It just seems redundant to have a master, then a send level, then a return level pot. On my HRM amps, the return level is the master but the difference is that on the HRMs I have a clean master too.

I will probably use a choke, Skyline with .1 bass, .01 mid caps and am leaning to using the precision PS but with the old style dropping string as it has worked well for me in the past.

See any pitfalls, here?

thanks

[jaysg]

MM has the FBFBM-OM and others with 4/8/16 ohm secondary. You may know someone who buys at the bulk order pricing.

[tubedogsmith]

As long as you're looking to go off the reservation a ways here's an idea. This amp is built with a TW style PT, plate B+ is around 390vdc, and the OT is a TW hybrid deal too with 4-8-16 ohm taps. 100k plates and it really, really sounds great. Here's a short thread about it.

https://tubeamparchive.com/viewtopic.ph ... highlight=

[odourboy]

One issue with leaving off the master is to ensure you still have the correct loading on the coupling capacitors or you may screw up the response.

[Structo]

Tonegeek,
On my D'Lite ( 2 x 6L6) I changed the OT to a Fender Prosonic OT rated for 50 watts with 4, 8 , 16 ohm taps.
The one that came stock was about 1/4 the size of this new one.

The change I experienced was a beefier tone with tighter bass.
I'm not good at flowery descriptors but I liked what it brought to the amp.

I bought it from Angela's but I'm not sure if it is still offered there.
GENUINE FENDER PART #049009

[M Fowler]

Take at look at ampparts direct.

http://stores.shop.ebay.com/amppartsdirect

Or triode http://store.triodestore.com/transformers.html

[Tonegeek]

As long as you're looking to go off the reservation a ways here's an idea. This amp is built with a TW style PT, plate B+ is around 390vdc, and the OT is a TW hybrid deal too with 4-8-16 ohm taps. 100k plates and it really, really sounds great. Here's a short thread about it. https://tubeamparchive.com/viewtopic.ph ... highlight=

Even though it looks like it, I really don't want to stray too far from the tried and true. The built in dlator is an exception, but one I have experience with already, so I mostly know what to expect there.
If the amp was for me, I would be inclined to experiment more and the 100k plates appeal to me for sure.

One issue with leaving off the master is to ensure you still have the correct loading on the coupling capacitors or you may screw up the response.

Good point. I was expecting to load it down by replacing the pot with a 1 meg resistor or a combination of coupling and bypass resistors to simulate the pot being in circuit. The recovery tube should be able to make up for any losses.

Tonegeek,
On my D'Lite ( 2 x 6L6) I changed the OT to a Fender Prosonic OT rated for 50 watts with 4, 8 , 16 ohm taps.
The one that came stock was about 1/4 the size of this new one.

The change I experienced was a beefier tone with tighter bass.
I'm not good at flowery descriptors but I liked what it brought to the amp.

I bought it from Angela's but I'm not sure if it is still offered there.
GENUINE FENDER PART #049009

I will check it out. I offered the MM, but they don't want to fork over the big bucks for it. I want to use the OT that HAD used if possible, or close to it, but actually my friend has signed off on the 2,4,8 Bassman OT so I am OK with that, but he also entertained the idea of using a Marshall 4X12 box and so I had to tell him you better run a full stack if you use the Bassman OT

[talbany]

100k plates or 220/150, or hybrid? This is a biggy. The friend I am building for likes the Lerche Youtube clips and so we are using that amp as a baseline. Consensus is that it is a high plate amp. The amps with the best clean sounds (my opinion only) are 100k amps. I have heard great OD sounds out of low and high plate amps, so I am leaning toward building a low plate version but from what I have read, there seems to be some trade-off with the OD sound if using all 100k plates. Is there a good compromise to get sweet, harmonically rich cleans, and get a fat OD

I have built a few amps using a 180-120 (150k slope if you like bass or 100k less bass).. Both work well as matter of taste.. for V1 .01 mid cap Skyline Classic..w/220/150 on the OD to keep it stiff and thick.. I personally like a 250k OD master...Keep the voltages on the low side 185-190 v1 200-205 area V2...This is the set up I used for the amp I built Jack Pearson posted a clip a while back..
the 180-120 seems to be a good middle ground for the high and low plate for me.. 180/150 also works well but I prefur the 120.. Good luck..


Tony VVT

[heisthl]

I have built a few amps using a 180-120 (150k slope if you like bass or 100k less bass).. Both work well as matter of taste..
Tony VVT

Actually you have that backwards, a smaller slope gives you more bass, use the tone stack calculator and put the bass on 10 and change the slope value to see what I mean.

[talbany]

Actually you have that backwards, a smaller slope gives you more bass, use the tone stack calculator and put the bass on 10 and change the slope value to see what I mean.

Henry
Thanks for the catching that!!



Tony VVT

[markusw]

FWIW, I built a 100k clean 220k/150k OD non-HRM hybrid and I really like the OD sound. I did however add Gil's OD entrance mod (6n) to reduce the bass content of the 100k cleans to approximate the 220k/150k cleans.
Edit: I totally agree that 100k cleans are better.

[Tonegeek]

FWIW, I built a 100k clean 220k/150k OD non-HRM hybrid and I really like the OD sound. I did however add Gil's OD entrance mod (6n) to reduce the bass content of the 100k cleans to approximate the 220k/150k cleans.
Edit: I totally agree that 100k cleans are better.

Now that appeals to me. Would love to hear a clip of the OD channel.
I am not familiar with that mod to the OD entrance. Can you post everything from the v1b coupler to the v2a grid stopper?

ALso, is yours a Skyliner with the 150k slope?
thanks

[markusw]

Now that appeals to me. Would love to hear a clip of the OD channel.
I am not familiar with that mod to the OD entrance. Can you post everything from the v1b coupler to the v2a grid stopper?

ALso, is yours a Skyliner with the 150k slope?
thanks

Sorry. It's embarassing but so far I didn't manage to do any clips.
However, we recently compared the 100k 220k/150k hybrid 50W head with an all 250k/150k preamp (actually built into a huge stompbox) by feeding the 220k/150k preamp into the return jack of the head and I can just tell you that the hybrid for sure didn't sound worse
Test was done with a Strat, btw.

Basically, the whole hybrid amp including tone stack is like in the "grail" schematics https://tubeamparchive.com/files/early_ ... v0_353.pdf
Only with 100k/1k5/10µ for both halves of V1 and a 6n ( 4n7 and 1n in parallel) cap paralleled by a 4M7 resistor in series in front of the 220k OD input resistor.
If OD is activated V1b output cap is connected to the 220k OD entrance resistor via the 6n/4M7 combo.

Hope this helps.

Peace,

Markus

PS: Maybe we will manage to do some clips in the next weeks but I wouldn't bet on it

[Structo]

OD entrance mod

[Tonegeek]

Now that appeals to me. Would love to hear a clip of the OD channel.
I am not familiar with that mod to the OD entrance. Can you post everything from the v1b coupler to the v2a grid stopper?

ALso, is yours a Skyliner with the 150k slope?
thanks

Sorry. It's embarassing but so far I didn't manage to do any clips.
However, we recently compared the 100k 220k/150k hybrid 50W head with an all 250k/150k preamp (actually built into a huge stompbox) by feeding the 220k/150k preamp into the return jack of the head and I can just tell you that the hybrid for sure didn't sound worse
Test was done with a Strat, btw.

Basically, the whole hybrid amp including tone stack is like in the "grail" schematics https://tubeamparchive.com/files/early_ ... v0_353.pdf
Only with 100k/1k5/10µ for both halves of V1 and a 6n ( 4n7 and 1n in parallel) cap paralleled by a 4M7 resistor in series in front of the 220k OD input resistor.
If OD is activated V1b output cap is connected to the 220k OD entrance resistor via the 6n/4M7 combo.

Hope this helps.

Peace,

Markus

PS: Maybe we will manage to do some clips in the next weeks but I wouldn't bet on it

O yea! This is where I yearn to go. I remember reading about that mod. I did a similar OD entrance mod on my BM that cuts the bass and also boosts the signal (hint- i put a ...) what the hell, here it is: the HRM uses 470k usually paralleled by 47p. I made another network that uses a 180k in series with a .0047 cap. You switch this thing across the 470k for a boost and more focus. I use it to get instant Hendrix/SRV tones. It brings out the Strat position 4 and 5 very nicely. Kind of a fat 18 watt Marshall sound to me. I posted clips of this on this thread (The hendrix one mainly): https://tubeamparchive.com/viewtopic.php?t=9355
I just noticed on the description that comes up when that clip is playing that it says Strat bridge. wrong, it is position 4. The 'focus' is the network i mentioned. Mid boost is on too, but even without it, it gets that sound, just a bit less in your face mids. (I use tamed mid boost of 500p) my unboosted treble cap value is the old Fender mainstay of 250p.

OD entrance mod

Looks like the .05uF might tighten up the bass slightly. Why do you need the 10 meg resistor (relay pop maybe)? What plate resistor value do you use on V1?