ods-101-hrm question

mat · Post by **mat** » Tue Jun 26, 2007 5:11 pm

On ODS-101-HRM schem (https://tubeamparchive.com/download/file.php?id=1179) there is .047 cap from CL2 that connects directly to the clean master pot. Is this how it should be ?

I'm having a bit of hard time to compare the schem and my HRM build (based on http://bad-domain/97HRM/97_ODS_HRM_Loop.JPG ). On the layout the signal goes from the cap only to the switch (relay) but on the schem it goes both to the switch and to the pot ?

chris_sanford · Post by **chris_sanford** » Wed Jun 27, 2007 12:22 am

mat wrote:On ODS-101-HRM schem (https://tubeamparchive.com/download/file.php?id=1179) there is .047 cap from CL2 that connects directly to the clean master pot. Is this how it should be ?

Yes, the clean master should always be connected to the .047uf coupling cap in the HRM design.

mat wrote:I'm having a bit of hard time to compare the schem and my HRM build (based on http://bad-domain/97HRM/97_ODS_HRM_Loop.JPG ). On the layout the signal goes from the cap only to the switch (relay) but on the schem it goes both to the switch and to the pot ?

Yes, the layout diagram doesn't look right to me. Clean mode is ok, but in od mode, the output of the overdrive section is unreferenced, and the clean master is disconnected from the v1b coupling cap. Do you have a link to the BrownNote HRM schematic? Perhaps that will clear things up...

chris

Bob-I · Post by **Bob-I** » Wed Jun 27, 2007 3:58 am

It looks to me like Norm's layouut is not exactly following Jake's ODS101 schematic.

IMHO the HRM amp should have 2 masters, one for each channel, where the nonHRM has an OD level, often called Ratio, and a master. Norm may disagree which is his right.

I believe we're way past trying to duplicate Dumble's amps, and into developing amps inspired by his but are our own.

Personally I'm thrilled with how my amps are sounding in band sitations. My Peavey transplant HRM sounds amazing with any guitar I've tried and the Tonker/SwampThang combo. I 'm driving clean channel to about 7 on the gain and it's just starting to crunch a tad. The ODS side i'm running at about 5 for a sweet singing OD, great chord definition and soling tone.

mat · Post by **mat** » Wed Jun 27, 2007 7:01 am

Yes, the clean master should always be connected to the .047uf coupling cap in the HRM design.

I have had problems with my HRM build the OD sounding not right and the balance between (with PAB on) OD and clean is not right, the OD being too weak. I'll try asap to put the wire in.

Yes, the layout diagram doesn't look right to me. Clean mode is ok, but in od mode, the output of the overdrive section is unreferenced

Sorry, I don't understand what the

the overdrive section is unreferenced

means (my bad english).

Any other spots that does not seem to be right/changed/designed on a new way ?

, and the clean master is disconnected from the v1b coupling cap.

I'll put the wire in.

Do you have a link to the BrownNote HRM schematic? Perhaps that will clear things up...

No I don't. I searched the BrownNote forum but did not find it. Would love to compare it to my build.

Thank You chris

mat · Post by **mat** » Wed Jun 27, 2007 10:42 am

Ok, I did put a jumper wire from CL2 coupling cap to the opposite side of the ground lug of the master volume pot. The sound got lot worse and there appeared lots of oscillations when turning the drive pot higher

It makes the comparing tougher (for me) because 101 schem does not have the RJ-switch but deep switch. On Norms layout the case is just the opposite.

stelligan · Post by **stelligan** » Wed Jun 27, 2007 10:54 am

mat,
I remember a thread on the BrownNote forum about a D'Lite HRM that Normster was noodling with. I don't think there was ever a schematic posted but, there was a layout picture. I can no longer find that thread either. Perhaps they are planning a production model of that unit?? I may still have a pic. Maybe Normster will chime in for you.

Normster · Post by **Normster** » Wed Jun 27, 2007 1:15 pm

That early HRM layout had a few mistakes which I fixed on-the-fly during my build. The relay wiring and clean/OD master wiring is not correct. As you found out, the CL2 coupling cap should be connected to both the relay and to the clean master. FWIW, the HRM101 schematic seems correct, so when in doubt...

mat · Post by **mat** » Sat Jun 30, 2007 1:37 pm

Normster wrote:That early HRM layout had a few mistakes which I fixed on-the-fly during my build. The relay wiring and clean/OD master wiring is not correct. As you found out, the CL2 coupling cap should be connected to both the relay and to the clean master. FWIW, the HRM101 schematic seems correct, so when in doubt...

Thanks for the answers everyone

I got little help and sorted the wiring problem (at least I think so). The OD on my amp is far smoother than earlier. I did a quick clip:

http://media.putfile.com/htp-hrm070630

Reverb and delay is from Alesis Microverb4 on the d-lator loop. I doubled the guitar track (SM57) on cubase without any further processing.

One odd thing is that now that the clean master and OD master works first time seperately the OD master is really loud at 1 or at 8 o'clock. Might still have some wiring error in

But the amp sounds far better than earlier

I swapped the V2 plate resistors from cc to RN65 and did a clip of both on the other thread.

dogears · Post by **dogears** » Sat Jun 30, 2007 4:13 pm

So Mat, the HRM is really getting better for you now...Eh???

mat · Post by **mat** » Sat Jun 30, 2007 4:36 pm

dogears wrote:So Mat, the HRM is really getting better for you now...Eh???

Yes Sir

I will try a thinner baffle for some more 'meat' for the tone... and wait for the Heritage G12-65...

kleinm · Post by **kleinm** » Tue Jul 03, 2007 12:59 pm

Cool mat! Glad to see you get the HRM closer to where you want it. This is sounding really nice.

mat · Post by **mat** » Tue Jul 03, 2007 7:38 pm

kleinm wrote:Cool mat! Glad to see you get the HRM closer to where you want it. This is sounding really nice.

Thanks kleinm

The amp really starts cooking now

I have to push the KT77's a little to get singing clean od that I've been seeking for. The recording does really not do justice for the amps sound. Have to upgrade the lousy micpreamp of mine.
I might try again 6V6(dont tell dogears

),6L6 and EL34's in there just to get the perspective of the different tubes in it. This is definitely different beast than the nonHRM.

I also changed the 22mm baffle to 8mm one adn prefer the latter for more 'complex' tone.

I really like dogears's 'Robbenesque' sound and also the Chuck's 'Blues in 3/G'-clip tone (nonHRM). Btw. those players phrasing remainds a bit of each other

Might there be a chance that another has been a influence/teacher to another

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