HRM needs some Lovin'
Moderators: pompeiisneaks, Colossal
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- Location: Montreal, Canada
Re: HRM needs some Lovin'
Hi guys,
I must say working on this project is challenging, and I try to live this as a labor of love. I do my best to keep going and not be discouraged by all the things that need to be done before I can fire this amp back again.
I have almost finished the main board. I have trouble attaching the pfiher pots because the eyelets of the board don't match the spacing of the pots.
If you have any recommendation, I am up to it. The pfiher pots looks to be very little to operate. I might end up gluing bigger ones and on the board and wire it to the eyelets if I can't find a good replacement.
After reading many threads on the forum, it seems like some cable should not run to close to others because of interferences and possible RF due to magnetic field generated by the trannies. It also looks like keeping the cables as short as possible is a best practice.
I have also started to overhaul the front panel to fit the HRM pots and then I realized that the amp layout is upside down : preamp tubes on the left side, trannies on the right side etc... It means that if I put the main board back with the tonestack located on the left, I will have to run all my cables opposite ways to connect them to the preamp tubes and pots.
Questions :
1- can I reverse the position of the board so that all wires coming out of the board are facing all their connectors ?
2- there are lots of cables to connect, trying to keep things tidy as much as I can, I would like to use plastic wrappers to keep them together. Can I tie the tonestack wires together? which ones should not mingle? I am trying to figure things out from layouts pictures on the forum, but It is not that clear to me.
Thanks.
Fred.
I must say working on this project is challenging, and I try to live this as a labor of love. I do my best to keep going and not be discouraged by all the things that need to be done before I can fire this amp back again.
I have almost finished the main board. I have trouble attaching the pfiher pots because the eyelets of the board don't match the spacing of the pots.
If you have any recommendation, I am up to it. The pfiher pots looks to be very little to operate. I might end up gluing bigger ones and on the board and wire it to the eyelets if I can't find a good replacement.
After reading many threads on the forum, it seems like some cable should not run to close to others because of interferences and possible RF due to magnetic field generated by the trannies. It also looks like keeping the cables as short as possible is a best practice.
I have also started to overhaul the front panel to fit the HRM pots and then I realized that the amp layout is upside down : preamp tubes on the left side, trannies on the right side etc... It means that if I put the main board back with the tonestack located on the left, I will have to run all my cables opposite ways to connect them to the preamp tubes and pots.
Questions :
1- can I reverse the position of the board so that all wires coming out of the board are facing all their connectors ?
2- there are lots of cables to connect, trying to keep things tidy as much as I can, I would like to use plastic wrappers to keep them together. Can I tie the tonestack wires together? which ones should not mingle? I am trying to figure things out from layouts pictures on the forum, but It is not that clear to me.
Thanks.
Fred.
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Re: HRM needs some Lovin'
Do you mean that your new board is OK but the previous owner build everything else following a "mirrored" layout?
I have no precise idea about the subject, but I'll sure be tempted to buy a new chassis and build that properly, at that point.
I have no precise idea about the subject, but I'll sure be tempted to buy a new chassis and build that properly, at that point.
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- Posts: 514
- Joined: Tue Jun 06, 2017 12:20 pm
- Location: Montreal, Canada
Re: HRM needs some Lovin'
Hi ChopSauce,
I have no clue why the builder of the amp has done thing in the opposite way.
I thought about re-doing the whole chassis. The problem is the wiring for all the tubes, power supply and power rectification.
I thought I would not touch the things that seems to work properly.
So in order to have the wires facing their connectors, I would have to flip the new board180 degrees.
I was wondering about what would happen if doing so (RF problems ? potential power oscillation? etc... ).
Otherwise, I have attached long enough wires on the board to have them run underneath . Not very Dumbly or kosher, but hey.. it is what it is
I am almost done wiring it. It is missing the two pots one for the PI and one for the OD trimmer
Did not test it yet.
Cheers.
Fred.
I have no clue why the builder of the amp has done thing in the opposite way.
I thought about re-doing the whole chassis. The problem is the wiring for all the tubes, power supply and power rectification.
I thought I would not touch the things that seems to work properly.
So in order to have the wires facing their connectors, I would have to flip the new board180 degrees.
I was wondering about what would happen if doing so (RF problems ? potential power oscillation? etc... ).
Otherwise, I have attached long enough wires on the board to have them run underneath . Not very Dumbly or kosher, but hey.. it is what it is
I am almost done wiring it. It is missing the two pots one for the PI and one for the OD trimmer
Did not test it yet.
Cheers.
Fred.
- norburybrook
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- Location: London
- Contact:
Re: HRM needs some Lovin'
you can splay out the legs of the trimmer pots. Most of my builds with pre made boards have had eyelets that didn't match with the pots. Some gentle persuasion with some needle nose pliers will sort that out.
M
M
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Re: HRM needs some Lovin'
@nordburybrook, thanks for the tip!
I will work on my nose plier persuasion skill set
I will work on my nose plier persuasion skill set
Re: HRM needs some Lovin'
You need a new chassis and built it right. Where do you live?
Mark
Mark
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Re: HRM needs some Lovin'
Mark, I live in Montreal Canada.
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- Posts: 514
- Joined: Tue Jun 06, 2017 12:20 pm
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Re: HRM needs some Lovin'
I could not get my hands on a 2K pot for the presence knob. I have a 1K and a 5K pot. I thought about using a resistor on the 1K pot to match the 2K requirement but then I will always have at least 1K resistance engaged in the circuit. Is there a way to trick it differently? Should I use the 1K or 5K pot ?
Fred, learning everyday!
Fred, learning everyday!
- martin manning
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Re: HRM needs some Lovin'
You can put a 3k3 across the outer lugs of the 5k and get 1.99k, or put 1k in series with 1k pot. A linear pot will have most of the tonal variation in the upper half anyway, so 1k plus 1k in series would be better for spreading the effect over the whole rotation.
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Re: RE: Re: HRM needs some Lovin'
Thanks Martin, much appreciated!martin manning wrote:You can put a 3k3 across the outer lugs of the 5k and get 1.99k, or put 1k in series with 1k pot. A linear pot will have most of the tonal variation in the upper half anyway, so 1k plus 1k in series would be better for spreading the effect over the whole rotation.
Fred, learning everyday!
Re: HRM needs some Lovin'
Fred, I'll check my 2k pot drawer their alpha.
Mark
Mark
Re: HRM needs some Lovin'
Seaside is still in operation. Terry could provide a clean fresh-start chassis.
See 1650HA OPT. Curious regarding the power transformer.
Best .. Ian
- dorrisant
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Re: HRM needs some Lovin'
Lookin' good so far! kudos for diving in to the deep end...
"Education is what you're left with after you have forgotten what you have learned" - Enzo
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Re: HRM needs some Lovin'
@Ian thanks for the reference I will definitely call them.
@Mark I think I can get along with Martin's option, but I really appreciate the gesture.
@Dorrissant thanks for the support!
Fred, learning everyday!
@Mark I think I can get along with Martin's option, but I really appreciate the gesture.
@Dorrissant thanks for the support!
Fred, learning everyday!
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- Posts: 514
- Joined: Tue Jun 06, 2017 12:20 pm
- Location: Montreal, Canada
Re: RE: Re: HRM needs some Lovin'
1650HA is the actual tranny used on this build.didit wrote:Seaside is still in operation. Terry could provide a clean fresh-start chassis.
See 1650HA OPT. Curious regarding the power transformer.
Best .. Ian
Fred, learning everyday!